This coupling inserts into one-inch polyethylene pipes to make connections or repairs. For use with flexible plastic pipes for cold water, or poly-pipe. This coupling is barbed on both ends to hold the fitting in place. The coupling can be inserted by hand. You should use worm-drive, and hose clamps on pressurized lines (sold separately). Not for use with compressed air or gas pipes.This coupling is made of ASTM D1784 and ASTM D2609 compliant PVC. ASTM standards assure it is weather resistant, robust against corrosion, and meets long-term stress and strength requirements. It is certified to NSF/ANSI 14 and 61, for health effects and performance of plastic piping components of potable water.