Specifications: Application scenario: Great for Sofa, Couch, Chair, Ottoman, Furniture, Cabinet, Shelves. Easy to install Height: Adjusts from 3.7” to 12? Material: The center is supported by thick stainless steel,Extra Durable,and the outside is wrapped in plastic,Electrophoresis black to prevent rust and corrosion Packing included: 4 pcs x Adjustable Height Furniture Leg;Features: 1.This product is designed to match different beds' heights to protect your bed and mattress from damage or sagging.2.The design is a cost effective way for maintaining the life of your expensive bedbase / Wooden Slat / Mattress Foundation / Platform Bed Frame / Box Spring .The bed frame support legs will hold and evenly distribute the weight of your heavy mattress efficiently protecting your bed and mattress from sagging and damage .Saving you money on bed repairs and mattress replacements.