These adjustable leg levelers are designed for custom kitchen cabinets, but we find they work great for garage storage cabinets. A set of four can support 775 pounds. They are adjustable from 3.64" to 6.2". Extensions are available to add an additional 1.97" per extension. Stack extensions if needed. The base plate for the leg screws to the bottom of the cabinet, the adjustable leg slips into the socket. Can be adjusted by hand or with a screwdriver. Price is for a screw in base socket and an adjustable leg. Extensions available separatly, see related products.