Sleds made of light metal, steel runners are used in Bobsleigh competitions. The 4-crew sleighs are maximum 12.5 ft long and weigh around 630 kg and 2-crew sleighs are 8.9 ft long that weigh around 390 kg for men and 340 kg for women. To protect the crew from bumps, the cowling is made of moulded fiberglass. The sled is designed to be aerodynamic to minimize wind resistance.