Two holes.
Zero pressure.

No — deliberately. Soft foam compresses until your sit bones press on the chair again. The high-density core is structured to maintain the openings during prolonged sitting. Expect support closer to a firm mattress than a plush pillow. Why firm beats soft over a long sit →

Because it is — on purpose. The mechanism depends on foam that doesn’t collapse. The adjustment is measured in days — most people coming from soft cushions acclimate within the first week — and the trial is measured in months. If week two still feels wrong, that’s what the rest of the 100 days are for. One softening trick some customers use: remove the cover and wrap the bare foam in a smooth pillowcase — the taut cover adds a little surface firmness of its own.

The openings are 3.5″ wide, spaced 6″ center to center. Because each opening is wide, sit-bone widths from about 3.6″ to 6.7″ land inside them — which covers the typical adult range of about 4″ to 6″. Adult anatomy varies — measure yours in 60 seconds and compare.

You’re not paying for more foam — you’re paying for the geometry: openings a specific size and spacing, contoured, in a core dense enough to hold them open under body weight. The full cost breakdown is in the Compare section — and if a cheaper pad solves your problem, it says so there too.

It measures 18.5″ wide, 14.5″ deep and 2.5″ tall, and needs about 18.5″ of flat seat width — fine on most office and dining chairs, and on flat-pan gaming chairs. A racing-style bucket with tall side bolsters often has less level pan than that, and the cushion will bridge the slopes and rock. In cars the added height helps many drivers see better, but it can feel tall in low-roof vehicles — check your headroom first. If the roof turns out closer than you guessed, that’s a free return inside the 100 days, not a cushion stranded in your trunk.

Designed for adults roughly 110–295 lbs, with openings spaced 6″ center to center to align with typical adult sit-bone width. A small number of adults measure below the 3.6″ this geometry is designed for, and nothing about build predicts it. Height, build and hip width barely predict sit-bone spacing — what your body actually tells you. In four published studies of adult sit-bone width, every group’s average landed inside the designed range — the numbers.

No — and it is the assumption that trips most people up. Sit-bone width follows the shape of your pelvis, not how tall or heavy you are. In the published measurements, height barely predicts it, hip width barely predicts it, and although women average about a centimeter wider than men, the two ranges overlap almost completely: a tall man and a petite woman can measure exactly the same. That is why we ask for one cardboard measurement rather than your height or your size — it takes a minute, and it is the only number that decides whether the openings land under your bones. Check yours →

Partly. The groove at the rear keeps your coccyx off the seating surface — but it is a groove, not an opening like the two under your sit bones, and the cushion is designed primarily around sit-bone geometry. If your pain is squarely at the tailbone and not at the two bones either side of it, a dedicated coccyx cushion is the better-shaped tool. We make one — the Aylio coccyx cushion (opens in a new tab) — and what the U-cutout does and the direct comparison are the two pages to read. How to tell which one you have →

The firm base creates its own platform, so it works on soft seating better than a soft cushion would — you won’t sink through. It does its best work on firm, flat seats; on a very soft or uneven surface (like a bed), results vary.

Less than a solid foam cushion does, and it is not air conditioning. The top layer is 3D spacer mesh — an open weave that holds a few millimeters of moving air between you and the foam instead of pressing a closed cover against you — and the two openings vent every time you shift your weight. A wrapped cushion warms because it holds you on every side; this one touches your thighs and glutes only. In a hot room you will still be warm. What the mesh takes away is the particular warmth a solid cushion builds up under you by hour two.

Mesh side up, openings toward the back of the chair, groove at the rear. Sit fully back so your sit bones settle over the openings. If you feel edge pressure, shift the cushion an inch forward or back. The five-minute setup guide covers the rest →

It weighs 2.5 lbs and has a carry handle built into the side, so it moves from the desk to the car to a dining chair without much thought. It needs about 18.5″ of flat seat width wherever it lands, and it raises you roughly 2″ — worth knowing before it goes into a car with low headroom. What changes inside a car →

Unzip the three zippers and remove the cover — machine wash cold on gentle, then hang dry. No tumble dryer and no iron: heat shrinks the mesh, and a shrunk cover will not go back over the foam. Never machine wash the foam; wipe it with a well-wrung damp cloth and let it air dry. Care and setup, with pictures →

Because that’s where we sell it. Amazon handles the checkout, Prime shipping, and free returns, and your order sits in your Amazon history like anything else you buy there. Our 100-day promise runs alongside Amazon’s own returns window, so if Amazon’s window has closed and you’re still inside 100 days, come to us directly. Every official listing, by country, is on where to buy.

Email [email protected]. A real person reads it — ask anything about fit, firmness, or returns before you spend a dollar.

No. The Socket Seat is an ergonomic seat cushion, not a medical device. If you have a medical condition or post-surgical needs, check with your doctor or therapist first — they’ll know what’s right for you.