The adjustable furniture leveling feet are made of sturdy metal, they are heavy duty, can withstand a load as heavy as 1325lb, they are very strong and durable. The specification of the coarse thread is 3/8”-16 UNC, the parcel is inclusive 4 T-nuts in match of the coarse thread bolts, if you want to use them for other matches, please confirm the other parts’ specification first. The furniture leg levelers can be used on chairs, tables, cabinets, dressers, benches, sofas, beds or any patio furniture, outdoor furniture in the circumstance that the floor is not even or you want to raise the furniture a little bit higher. The parcel is also inclusive of 8 pieces felt pads which can be used to protect your floor from scratches or eliminate any noises. The leg levelers are easy to install, you need to have a drill and hammer to start your DIY projects. The adjustable furniture leveling feet kit is inclusive of 4 pieces 3/8”-16 UNC coarse thread bolt, 4 pieces Tnut and 8 pieces felt pad, they can be used on furniture in the circumstance that the floor is not even or you want to adjust your furniture’s height, the products are made of sturdy metal withholding a load of 1325lb, they are easy to install, perfect for your DIY project.