Elpro Slide Guide Shoe, Freight Swivel, 18SS for 3/4″ rail. Set of 4. The spring loaded shoe hugs the rail at all times. The swivel shoe is designed for automatic alignment. The gibs can be replaced without removing the base from mounting. Energy efficient aluminum shoe. Gib created from UHMW Polyethylene. Height: 10?, depth: 9-1/2?, width: 8-1/4?, gib length: 7-7/8?, base depth: 5-5/8?, weight 25 lbs. Rated capacity: 20K lbs per car.