High Density Chrome Wire Shelving Sliding Track System offers a unique way to maximize and efficiently move Wire shelving systems. The patented design allows for quick and easy installation. Bearings in the skate are located under each post for a load capacity of 1,500 lbs. per shelving unit. The V-groove floor track allows the shelving unit to slide back and forth with ease. Each kit includes two skates and all appropriate hardware. One kit is required for each single mobile unit. Ordering Instructions: (Note: Shelves and posts to be purchased separately) Step 1 - Select desired length of track and if you require: Single Unit track or Double Unit track Step 2 - Select corresponding skate size for single or double units. Skate size should match the depth of shelving unit being utilized. (Note, post height should not exceed a 4 to 1 ratio of skate size) Step 3 - Determine how many shelving units will fit on your track. Step 4 - Preconfigured 4-Shelf Wire units are available, sold separately.