ATP Transmission Seals and Gaskets are exact fit, no compromise replacement parts. The company first supplied automatic transmission replacement parts and, over the years, has expanded its product offering to include automatic transmission filter kits, repair kits, cables, flywheel and ring gears, cabin air filters and chemicals. In 2001, the Graywerks by ATP line was introduced. This line consists of exhaust manifolds, harmonic balancers, timing covers and engine and transmission pans.