Front view of the South Bay Sofinity Hybrid Signature 12-inch medium firm Euro top mattress on a blue upholstered bed frame in a modern bedroom setting.

Three-quarter angle of the Sofinity Hybrid Signature 12-inch mattress highlighting the thick Euro top and premium navy blue piping.

High-angle view showing the white tufted quilted surface of the South Bay Sofinity Hybrid Signature mattress on a contemporary blue bed frame.

Close-up detail of the Sofinity Hybrid Signature Euro top mattress showcasing the high-quality stitching, breathable side fabric, and blue accent trim.

Top-down studio shot of the South Bay 12-inch Sofinity Hybrid Signature mattress highlighting the plush quilted Euro top pattern.

Frontal studio product view of the 12-inch thick Sofinity Hybrid Signature medium firm mattress by South Bay against a clean background.

Perspective studio view of the Sofinity Hybrid Signature mattress highlighting its durable hybrid construction and patented edge support.

Technical cross-section diagram of the Sofinity Hybrid Signature mattress layers: breathable Sofinity foam, cooling comfort layer, and responsive hybrid support system.

Sofinity Hybrid Signature, Sofinity Foam, Patented Edge Support - Medium Firm Euro Top 12 inch Mattress By South Bay

Plush Medium Firm Pillow top Memory foam Hybrid

Sofinity Hybrid Signature, Sofinity Foam, Patented Edge Support - Medium Firm Euro Top 12 inch Mattress By South Bay

$788.00

$999.00

Save $211.00

Brand:

SOUTH BAY

i Size Guide

$788.00

Only 12 left in stock

Free USA Wide Delivery

10 Year Warranty

Advanced Technology

The South Bay Sofinity Hybrid Signature Mattress brings together luxurious Euro Top comfort and advanced Sofinity Foam technology in a premium 12-inch hybrid build. Cloudy Mattress is the authorized South Bay retailer for this product, so every purchase comes with trusted sourcing and the full manufacturer's warranty.

The feel sits comfortably in the medium-firm range of the comfort scale, balancing pressure-relieving comfort with the responsive support of a premium hybrid coil system. Because of this versatile feel, it ranks among the best Euro Top mattresses for back pain options for back, side, and stomach sleepers alike.

Inside, multiple engineered layers work together, starting with a pressure-relieving Euro Top layer sewn flush to the mattress for cloud-like surface comfort. This 12-inch Euro Top hybrid mattress uses Sofinity Foam underneath, engineered with roughly twice the airflow of traditional foam for enhanced temperature regulation. Furthermore, the Sofinity Foam contours effortlessly to the body, supporting targeted spinal alignment while keeping the surface lightweight and breathable.

A gel-infused cooling layer adds extra heat dissipation, helping create a cooler sleep surface for hot sleepers throughout the night. The mattress also features individually wrapped pocketed coils that deliver responsive lift with superior motion isolation for couples sharing the bed.

A M-Guard patented edge support system reinforces the perimeter, adding roughly 20% more usable sleeping space and a steadier sitting edge. Together with high-density Sofinity foam beneath the comfort layers, these components deliver durable no-sag mattress construction night after night.

The Air Channel™ base foam promotes airflow through the core, enhancing breathability and adding flexibility for adjustable-base setups. At a full 12-inch profile, this medium-firm pocketed coil mattress is fully adjustable-base compatible and pairs seamlessly with modern foundations.

Together, these layers deliver a cloud-like Euro Top comfort with the structured support of a hybrid coil core for a restorative deep sleep experience. Additionally, it arrives via hybrid mattress in a box delivery, compressed and rolled for convenient setup, and is backed by a 10-year manufacturer's warranty.

Plush Euro Top Comfort

A pressure-relieving Euro Top layer sewn flush to the mattress delivers cloud-like Euro Top comfort for the entire sleep surface.

Sofinity Foam Technology

Proprietary Sofinity Foam delivers ergonomic body contouring with roughly twice the airflow of traditional foam for a cooler, more breathable sleep.

Balanced Medium-Firm Feel

This medium-firm pocketed coil mattress suits back, side, and stomach sleepers with balanced pressure relief and reliable support.

Pocketed Coil Hybrid Support

Individually wrapped pocketed coils deliver responsive support with superior motion isolation for couples sharing the bed.

Patented Edge Support

The M-Guard patented edge support system reinforces the perimeter, adding roughly 20% more usable sleeping space.

Durable Long-Term Build

High-density Sofinity foam combined with the coil core delivers durable, no-sag mattress construction for years of consistent comfort.

Certified Clean Foams

All foams are CertiPUR-US certified foam and non-toxic certified materials, made without formaldehyde, phthalates, heavy metals, or ozone depleters.

Key Mattress Benefits

7 Layers
Of Cooling
Comfort

This top layer is sewn flush with the mattress edge to deliver a plush, cradling surface across the entire sleep area. As a Euro Top construction, it provides a more even feel and a cleaner look than traditional pillow tops.

This layer is South Bay's proprietary Sofinity Foam, engineered with roughly twice the airflow of traditional foam for enhanced temperature regulation. The lightweight, open-cell structure contours effortlessly to the body while promoting healthy spinal alignment.

This layer adds plush, cooling gel contouring that helps dissipate body heat. As a result, sleepers benefit from cradled comfort at the shoulders and hips with a cooler surface feel.

A reinforced perimeter is built into the mattress to extend the usable sleeping area by roughly 20%. This system also provides a stable sitting edge when getting in and out of bed.

This core layer is built from individually wrapped pocketed coils that deliver responsive support and gentle bounce. Furthermore, the pocketed design reduces motion transfer between partners while promoting airflow through the core.

This bottom layer reinforces the structural integrity of the mattress with integrated channels that promote airflow. It anchors the entire build, supports long-term durability, and helps maintain a consistent shape over time.

The exterior breathable stretch-knit mattress cover unzips for easy laundering and helps reduce allergens with regular washing. Its breathable design complements the Sofinity Foam and gel cooling system at the surface of the mattress.

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Euro top comfort is subtle - more medium than medium-soft

The mattress is superbly constructed and the Sofinity foam is excellent. My note is the Euro top adds comfort but reads more as a refined medium firm than a plush surface. If you want medium firm with just a hint of cushion this is exactly right. If you're expecting a noticeably plush surface the difference is real but subtle. Calibrate expectations accordingly.

Euro top elevates the Sofinity Hybrid to another level

The standard Sofinity Hybrid is excellent. The Euro top version takes it further. The seamlessly integrated comfort layer adds plushness that feels genuinely luxurious without compromising the medium firm support underneath. Same coil quality same patented edge support same Sofinity foam - but the Euro top makes the surface experience premium. Worth the upgrade.

Euro top is flush mounted - no shifting ever

Pillow tops shift and bunch over time. The Euro top is integrated into the mattress construction and has not moved in four months. Consistent feel across the whole surface every night. That structural integrity is the core advantage of Euro top over pillow top and South Bay executed it correctly.

Medium firm Euro top - the perfect balance for couples

My partner likes plush I like firm. We've argued about mattress firmness for six years. The Sofinity Hybrid Euro top lands exactly between our preferences. Medium firm provides his support the Euro top gives me the cushioned surface I want. Neither of us is fully happy in isolation but together it's the first mattress where we've both stopped mentioning it. That means it works.

Sofinity foam in the Euro top responds faster than memory foam

The Sofinity foam rebounds quickly making position changes seamless. When I roll from side to back the Euro top adapts immediately rather than holding the previous shape. On a medium firm mattress that responsive surface makes every position comfortable from the first moment. South Bay chose Sofinity foam for the right reason.

HAVE QUESTIONS?

WE'VE GOT ANSWERS

Designed for deep comfort and better rest, so you wake up refreshed and ready for the day

A Euro Top is sewn flush with the mattress edges, creating a clean, seamless look and a more uniform feel across the entire sleep surface. A Pillow Top sits on top of the mattress like a separate cushion, often with a small gap visible between the pillow top and the main mattress body. Euro Tops tend to feel slightly more supportive and tend to last longer due to the more secure construction.

Yes, the Sofinity Hybrid Signature is well-suited for side sleepers, especially with its plush Euro Top layer. The Euro Top combined with Sofinity Foam and gel memory foam, cradles the shoulders and hips where side sleepers need cushioning, while the pocketed coil core delivers underlying support to keep the spine in healthy alignment.

A box spring is not required. The mattress can be placed on a continuously solid surface, an adjustable base, or slats spaced no more than two inches apart. Cloudy Mattress also offers an optional box spring with a metal foundation as an add-on at checkout.

The mattress may take up to 72 hours to fully recover its shape after unboxing. You can sleep on it right away, as body heat and movement help speed the expansion process along.

Yes, all foam layers in this mattress are CertiPUR-US certified. They are made without formaldehyde, phthalates, ozone depleters, heavy metals, PBDEs, or listed Tris flame retardants, and they meet low-VOC standards for healthier indoor air quality.

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