CRESLINE 3/4 inch Nominal Size, CTS, 7/8 inch Outside diameter, 100 feet Coil Length, 0.097 inch Wall Thickness, SDR 9, 250 psi Working, Polyethylene, Spec: ASTM D2737, AWWA C901, NSF 14/61. Conforms to performance specifications for appropriate working pressures. Approved by National Sanitation Foundation for drinking water use. Made of black virgin polyethylene. Requires special copper tube size connectors.