The Sioux Chief Test Titan, mechanical test plug has an innovational approach with a proven performance. Polypro wingnut, nylon top plate, soft PVC gasket, and nylon base/stem for simplicity and strength. For head tests. Provides a leak-free seal at over 8 times the PSI of other mechanical test plugs. Back to front wedge design prevents blowouts at high and low temperatures. Nonslip shoulder for fast, easy installation.