High quality material The furniture risers are made of strong zinc alloy and felt pads, the felt pads at the bottom protect the floor and reduce noise. Easy to use Keep furniture legs dry and clean, put on foot pads. Adjust the height of the pedal. Secure the screws with the tool. Finish Adjustable from 2-5/8" to 4" The chairlift can be raised at least 7 cm and can be raised 10 cm by swiveling. The chairlift is ergonomically designed. By adjusting the direction and height, there is no need to worry about the humpback problem caused by the low chair. 45 swivel design The back of the chair can be adjusted freely at 45, without worrying about the uneven floor, which solves the tilt problem of traditional chairs. The chair can be moved freely without falling. Check size fits furniture legs 3-4cm (1-1/8"-1-5/8") in diameter, supports 20,000 lbs and can be used for beds, sofas, cabinets, etc.