TRX is an exercise program developed by Randy Hetrick. Hetrick is a former U.S. Navy SEAL who first designed a new type of suspension exercise equipment using a jiu-jitsu belt and parachute webbing. He continued to refine his ideas and officially launched his company in 2005. TRX, which is based in San Francisco, sells products to be used at home, in gyms, and in tactical training. The company's suspension trainers are intended to help users improve mobility, flexibility, strength, and endurance. Many of the items are portable and come with accessories needed to use them indoors or outdoors. They rely on gravity to provide resistance, and users of various strength levels can use the same equipment.