Use screw clamp adjust fixing, wrapped furniture legs are not easy to fall.3 cm grooves sinking, when you moving will not tilt.Added height not only make usable space under beds, but also allows vacuum cleaners or robot vacuum work more flexibly.Avoiding shoulder pain and neck pain caused by low height of furniture.They also make more convenient for the elderly to get in and out of bed.Made of heavy-duty strong hard plastic, which can stand the weight of the heaviest of furniture in your home or office, they can safely support a of up to 20,000 lbs.High density bottom felt pads protect your hardwood, ceramic tile linoleum floors and carpet from scratches and scuffs.Colour:blackMaterial:plasticPackage Contents:4 x Chair RisersOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.