If you want a unique, temperature-neutral GelFlex Grid that adapts instantly to your chair's firmness without changing layers, choose Purple Double Seat Cushion; if you need customizable height options and removable memory foam layers for deep coccyx support across multiple surfaces, choose PRIMART Memory Foam Seat.
• Purple Double Seat Cushion: Its biggest strength is the proprietary GelFlex Grid technology that stays cool and bounces back instantly; its trade-off is a fixed 2-inch profile that cannot be thickened for extra lift. This pick is for users who prioritize airflow and dynamic pressure relief over adjustable thickness.
• PRIMART Memory Foam Seat: Its biggest strength is the ability to customize height between 2 and 3 inches and swap firmness levels easily; its trade-off is standard memory foam which can retain more heat than gel grids and requires manual layer adjustment. This pick is for heavy-duty sit-comforters needing specific ergonomic lifts for sciatica or tailbone pain.
The Purple Double Seat Cushion is built around a single, powerful concept: the GelFlex Grid. Unlike traditional foam that compresses and slowly recovers, this grid structure uses hundreds of tiny air channels to distribute weight while allowing constant airflow. If you sit in an environment where heat builds up quickly—whether it is a stuffy office chair or a hot car seat during summer—the temperature-neutral material is a game-changer. The design cradles your tailbone specifically, spreading pressure away from sensitive areas rather than just sinking into a soft pocket.
What makes this cushion unique is the "flip" mechanism. You do not need to remove layers or change settings to alter how it feels. Flipping the cushion over switches between a small-grid side for a softer feel and a large-grid side for firmer support. This means you can adapt to different seating situations instantly without fumbling with straps or zippers. The non-slip bottom ensures the cushion stays put on smooth office chairs or vehicle seats, and the washable cover with built-in handles makes transport effortless.
However, this product is not for everyone. The fixed 18 by 16 by 2-inch dimensions mean you cannot add height to the cushion if your current chair is too low or if you require significant elevation for leg clearance. If you have severe mobility issues requiring a higher sitting surface or need to stack padding to reach a comfortable eye level with a desk, the single 2-inch profile might fall short. Additionally, while the grid is durable, it offers a very specific type of bounce that some users accustomed to dense, plush memory foam might find too firm or unusual initially.
We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-11-07 · 6 min read · Independent comparison
The PRIMART Memory Foam Seat targets users who need precise control over their seating geometry. Its standout feature is the adjustable multi-layer design, which allows you to switch between 2-inch and 3-inch heights. This customization is critical for individuals dealing with specific pain points like sciatica or coccyx injuries, where even an inch of extra space can change everything. By adding or removing layers, you can tailor the firmness from soft to firm, creating a personalized support system that adapts as your body's needs change throughout the day.
This cushion is designed for versatility across a wide range of furniture. The 17 by 17.5-inch footprint fits most standard office chairs, car seats, wheelchairs, and even airplane seats without feeling bulky. The inclusion of two separate breathable cotton covers—one for each height configuration—means you can keep the setup clean and hygienic easily. The memory foam contouring helps distribute pressure across the hips and tailbone, providing a stable, supportive surface that reduces fatigue during long hours of work or travel. The non-slip base works effectively to keep the cushion secure, whether you are driving or working from a home office.
The trade-off here lies in the nature of the material itself. While the memory foam offers excellent contouring and pressure distribution, it does not possess the same active cooling properties as a gel grid. Over extended periods, especially in warm conditions, the foam may retain more body heat compared to the open-channel design of other materials. Furthermore, the process of adjusting the height requires stopping, unzipping, or rearranging layers, which lacks the instant gratification of flipping a reversible cushion. It is a superior choice for those who value structural adjustability over dynamic material responsiveness.
• Best for temperature regulation → Purple Double Seat Cushion (GelFlex Grid keeps air moving constantly).
• Best for height customization → PRIMART Memory Foam Seat (Switch between 2-inch and 3-inch profiles).
• Best for immediate firmness adjustment → Purple Double Seat Cushion (Flip the cushion to change support instantly).
• Best for severe tailbone/coccyx pain → PRIMART Memory Foam Seat (Deeper contouring and added height options provide targeted relief).
• Best for wheelchair or scooter users → PRIMART Memory Foam Seat (Designed explicitly for these surfaces with high stability).
• Best for long-term durability → Purple Double Seat Cushion (Grid bounces back without going flat; memory foam can eventually soften permanently).
• Best for all-day office use → Both are strong, but Purple wins on cooling while PRIMART wins on ergonomic lifting.
For my own setup, I would choose the Purple Double Seat Cushion because the cooling factor and the instant flip capability solve the two biggest complaints about office seating: overheating and stiffness. However, if you are an atv owner looking for a cushion that can handle rugged vibration while providing the specific lift needed to reduce strain on your lower back and tailbone after long rides, the PRIMART Memory Foam Seat is the smarter investment. The ability to add that extra inch of height and firmness is crucial for maintaining posture in a vehicle that often lacks adequate suspension comfort. Ultimately, if you prioritize staying cool and responsive, go with Purple; if you need to physically elevate your sitting position for pain management, PRIMART is the clear winner.
Yes, the Purple Double Seat Cushion uses a GelFlex Grid with hundreds of air channels that allow air to flow freely, keeping the surface temperature neutral compared to standard memory foam which tends to trap heat.
No, the Purple cushion has a fixed 2-inch thickness, whereas the PRIMART model allows you to adjust the height between 2 and 3 inches by adding or removing layers.
While both offer pressure relief, the PRIMART Memory Foam Seat is generally better for sciatica because the option to increase height and firmness provides deeper ergonomic support for the coccyx and hips.
Yes, both products feature removable, machine-washable covers. The Purple cushion has a washable cover with handles, and the PRIMART includes two separate covers for different height setups that are also gentle on skin.
As an Amazon Associate I earn from qualifying purchases.
We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon and affiliated sites.
When you buy through links on this page, we may earn a commission from qualifying purchases at no extra cost to you.
Amazon and the Amazon logo are trademarks of Amazon or its affiliates. This site is an independent third-party review and is not affiliated with, endorsed by, or sponsored by Amazon or the product brands mentioned.