The clamp opens 8 to 25mm, wide enough for a tray table edge, a seatback tray lip, a luggage handle, or a treadmill console, and holds an iPhone by MagSafe with a magnet strong enough to snap into place in about a tenth of a second. It rotates a full 360 degrees between portrait and landscape and is compact enough to toss in a bag. Lists for $14.99, though it’s frequently discounted toward $9–10.