Stackable and adjustable. Just snap them together for taller heights or use individually for 2-inch adjustments. Perfect for under furniture to get under for cleaning or hovering in place.","8-pc set designed for heavy-duty use. Durable mesh reinforcement provides strong support. Non-slip rubber pad prevents slippage, keeping your chair stable under furniture. Stack up to 4 inches tall for easy access to tabletop or storage space.