<I>Superior quality, high end rack and pinion system!</i>The KV8092 4x4 pocket door slide is ideal for use in large entertainment and home theater cabinets. It is specially designed to hold over-sized doors up to 75 pounds and 72 inches in height. Dual rack and pinion system virtually eliminates door sag. Three-way adjustable isometric door hinges sold separately.For each door order: 1 set of 2 slides, 1 pinion shaft, 2 pair of 2 hinges, listed below