Every question, answered.

Soft, shifting surfaces are the design brief. A narrow cup sinks into cushions; the wide flexible base spreads across them, and the fins keep the drink seated when your weight shifts the seat. Bumped off level, it settles back.

Not for this, because nothing here clamps to an arm. Arm-mounted gear wants about 6 inches of flat width to sit stable, which apartment-size sofas rarely offer. This sits on the cushion beside you, the rug, the bed — wherever the drink actually needs to be.

It doesn't touch the apartment in any way a book doesn't — no clamps, screws, adhesive, or drilling, nothing for a walkthrough to find. It also earns its keep there: a drink that resists tipping is cheap insurance over carpet the deposit answers for.

Yes. Balcony slabs are built with a drainage slope, so nothing out there is truly level — the flexible base conforms to the grade and holds the drink steady on it. Wind plus an open can is still wind plus an open can; a lidded bottle is the move on a gusty day.

Reasonable — deposit guidance treats drink stains as damage, not wear, so that fear has a dollar figure. A stemmed glass is the most top-heavy thing in the apartment, and its wide flat foot sits squarely in the base range the fins are shaped for. It resists tipping rather than sealing the wine in: it stacks the odds, it doesn't repeal physics.

Bedding is the softest surface in the home, and that's exactly what the wide base is for. It rides the duvet instead of sinking in, and when a knee moves the comforter, the base flexes and the drink comes back level.

The sleek can is the tippy one — tall, narrow, light, open on top. Its base sits inside the about-2-to-3-inch range, so the fins grip it down low, where the leverage is. Standard cans and tallboys fit the same way.

Measure the bottom, not the top. A base of 2 to 3 inches across fits — the 40 oz Stanley does, and so do 32 oz insulated bottles. Handled mugs don't; the handle lands where a fin needs to grip.

That's exactly when drinks scatter to sills and floors. Set a couple where people actually land — the rug, the floor pillows — and floor-level drinks get footing and grip instead of a spot in the walking lane.

At least as well as on soft ones. The wide footprint and the fin grip keep a bumped drink from skating or going over, which a crowded coffee table appreciates as much as a cushion does.

Rinse it, or put it in the dishwasher. It's a single piece of flexible molded material with nothing to disassemble.

It's called the Steadi, molded in small runs in Orange, California by Steadi Labs — veteran-founded and patent pending. Orders ship free from steadilabs.com, and there are 30 days to change your mind.

It's a single piece of injection-molded flexible material — no clamps, hinges, springs, or fabric to work loose the way the clip-on trays and fabric caddies do over repeated use. There's no seam or joint to re-tighten; the whole thing is one molded part.

It fits that gift problem well: someone moving into a first apartment, a studio, or a walk-up doesn't need more furniture, they need something that works on whatever surfaces they end up with — cushion, duvet, balcony slab — before they've even arranged the place. Nothing clamps to anything, so it works before a new tenant owns a coffee table or knows their sofa arm's width.

More than most people expect, and not because any one wears out. The same person tends to want it on the couch cushion at movie night, on the balcony slab Saturday morning, and on the duvet on a studio Sunday — three different rooms in the same week. One that moves with you covers fewer of those moments than a few that live where you actually land.

Arm trays and clip-on holders assume a flat, rigid mounting surface of a specific width — reviewers of that category report constant re-leveling and wobble specifically on the rounded, pillow-topped arms that apartment-size sofas favor to save inches, and each design only fits a band of arm widths to begin with. This doesn't clamp to an arm at all, so arm shape and width stop being the question; it sits on the cushion, the rug, or the duvet instead, wherever the drink actually needs to be that day.

Not really — the fins grip the outside of the container's base, not the surface under it, so a takeout cold cup that's sweating and slick on its own bottom still seats the same way; the grip doesn't depend on dry friction against a table. A handle-less camp mug sits fine in the same base range; a mug with a handle doesn't, because the handle lands exactly where a fin needs to grip.

Floor-level drinks take the worst of it — they sit at ankle height, in the walking lane, and get caught by feet, tails, and passing roommates before anyone means to. The wide base and the fins mean a bumped drink resists tipping the way a bare glass on carpet pile typically would; a direct hit from something moving fast can still move any object that isn't bolted to the floor. Keeping it a step back from the main walking line still helps.

It's suited to exactly that kind of impermanence: nothing is clamped, glued, or screwed to the old place, so packing it is the same as packing any of the mugs and cups it protects — into a box, out at the new address, with nothing to reinstall and no new sofa arm or railing profile to check for fit.

Not really — it's one small piece of flexible molded material, not a tray or a stand, so it goes in a drawer, a cabinet shelf, or a bag between uses instead of claiming a permanent spot in a room that already has no spare surface to give up.