First developed in the 1970's, continuous improvements over the years has proven these belts are durable and work for many racing applications (with the exception of Alcohol and Fuel classes). These rubber belts have a fiberglass tension member, neoprene backing and teeth with a tough nylon facing for low friction and high wear resistance. These belts have excellent flex life, high resistance to elongation and good stability. These belts can be back bent around an idler pulley. Offered in both GT and HTD tooth profiles it should be noted that HTD belts can be used with either GT or HTD tooth profile blower pulleys. However, GT belts should only be used with GT tooth profile blower pulleys.