The chair riser is made of heavy duty hard plastic, and the waterproof design keeps the furniture from wet. Each riser raises furniture 4 inches, supports 20,000 lbs, and has felt pads on the bottom to floors from scratches and . The sofa riser is adjustable. The 4inch lift bed and furniture riser fits 0.86-1.57inch (22-40mm) furniture legs. note that the bed does not fit folding or reclining chairs, only right-angle chairs. Colour:black Material:plastic Package Contents: 4 x Adjustable Bed Risers Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.