Every question, answered.

That's the whole reason it's shaped this way. The wide flexible base spans a rail cap that's only a few inches across, and the fins keep the can or tumbler from walking sideways when an elbow catches it or the wind picks up. Bump it and it settles back instead of going over.

Wind is exactly what a bare rail cap can't defend against on its own — it's the highest, most exposed ledge on the deck. The wide base and the fin grip hold the drink steady against a gust; it resists tipping, it's not weightless magic, so a direct hard shove off the edge is still a direct hard shove.

Measure the bottom, not the rim. A base 2 to 3 inches across settles in — the 40 oz Stanley does. A koozie can push a can past that range, and handled mugs don't fit at all; the handle gets in the way of the fins.

No. Nothing clamps to the cap, nothing screws into the composite or the wood. It sits on top, works on any rail profile, and comes with you when you move to a chair.

Yes — hard, flat, and uneven surfaces are where it holds steadiest. The same base that bridges a rail cap bridges a board gap the same way.

Both work. The wide footprint and the grip are what keep a bumped drink from sliding off a hinge or an umbrella-shaken tabletop — set it anywhere flat-ish and it holds.

A straw cup or sippy cup within the base range settles in the same as a can does. It's not a lid or a seal, so it holds the cup steady — it doesn't replace one with a lid.

Rinse it off or run it through the dishwasher. It's one piece of flexible material with nothing to unscrew or take apart.

It's called the Steadi, molded in small runs in Orange, California by Steadi Labs. Every order ships free from steadilabs.com, with 30 days to change your mind.

Yes — it's a real second path, not just the rail cap. Code caps the opening between balusters at under 4 inches so a body can't fit through, but a standard can's roughly 2.6-inch base slips through that same gap with room to spare. The base sits on top of the rail cap itself, well clear of the spindles below, so there's nothing parked at baluster height to fall through in the first place.

That's the setup where a rail-cap spill matters most — whatever goes over lands on the patio, the storage, or the people underneath, not just the deck floor next to the chair. The wide base and fin grip resist tipping through the ordinary causes of a rail-cap loss: an elbow reaching for the tongs, a passing gust, someone brushing by on the way to the cooler. A hard, deliberate knock off the edge is still going over the edge; what the base and fins change is the everyday bumps that cause most of those losses to begin with.

Deck boards sit right in dog-tail and foot-traffic territory — ankle height, no lid, nowhere to go but sideways into a gap. The wide base and fin grip hold a can or tumbler through a glancing knock and settle it back level instead of letting it walk toward the nearest gap. A direct hard hit is still a hard hit, but the everyday brush-past is exactly what the base and fins are built to hold through.

It's one piece of molded material, not a mesh loop, a suction seal, or a hinge — there's no fabric to fray, no seal to degrade, and no spring or clamp hardware to work loose the way a rail-clamp cup holder's hardware does after a season of sun, rain, and freeze-thaw outside.

Yes — the fins grip a can by its bottom inch whether it's dry or slick with condensation, because the hold comes from the fins wrapping the base rather than from friction against a wet surface, which is what a bare rail cap or a bare hand has to rely on instead. A sweating, half-empty can is exactly the kind of light, slippery drink the wide base and fin grip are built to hold steady.

One per drink is the simplest rule of thumb — the grill area usually wants its own near the tongs, plus one per chair or spot around the cooler once people settle in. It comes in a few colors, which doubles as a way to tell whose can is whose once they all start looking alike after dark.

It solves a problem the deck itself never solves on its own — nowhere flat, dry, or gap-proof to set a drink on the rail or the boards — so it lands well for anyone who just inherited a railing, an Adirondack chair, and the cookout-hosting duties that come with them.

No. Clamp-style rail holders are built for one profile, usually a flat 2x4 or 2x6 wood cap, so a contoured composite or aluminum rail defeats them outright. This doesn't clamp to anything — it sits on top, so pressure-treated wood, composite, and aluminum rail systems all hold it the same way.