[Hard Plastic Material]Adjustable furniture risers are made of heavy-duty, tough plastic that can withstand the weight of the heaviest furniture in your home or office, and couch risers can safely support a total of up to 20,000 pounds. Bed risers 4 inch will not crack like other risers. The high-density bottom felt pad will protect your floors and carpets from scratches. [Upgrade Screw Clamp Fixed & Not Fall Off]Unlike other bed risers without clamping devices, any slight movement may cause the unstable riser to fall from the foot of the furniture, while our desk riser holds the frame with the help of the clamping frame structure and will not fall when lifting and moving the furniture. [Adjustable Chair Leg Width]4 Inch lift bed and furniture risers fits 0.8-1.6 inch (22-42mm) straight legs of furniture. Adjustable design of sofa riser can protect furniture legs from falling off. Total height: 5.2 inch, actual height increase: 4 inch. TIPS: Not suitable for width legs smaller than 22mm (0.8 inch) and not suitable for width legs more than 42mm (1.6 inch). [Create Usable Space]Bed lifts risers can increase the height which creates more storage space under the bed and allows the vacuum cleaner to work more flexibly. They also avoid shoulder and neck caused by low furniture height and easier for the elderly to get in and out of bed. Bed risers heavy duty can add 4 inches of height to beds, sofas, armchairs, tables, couches, and other heavy fixed furniture. [Not Compatible with Any Inclined Legs]Not compatible with any furniture with inclined legs. Therefore, please confirm the size and shape of your furniture before purchasing. Colour:black Material:plastic Size:5.5 x 13.4cm Package Contents: 4 x Furniture 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 picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.