SMC KQ2P-07 PBT Push-To-Connect Tube Fitting, Plug, 1/4" Tube OD Plug for closing the end of a pipe or fitting Accepts nylon and polyurethane tube fittings Made of polybutylene terephthalate (PBT) for resistance to solvents, shrinkage, heat, and impact Working pressure of up to 145 psi Operating temperature ranges from -5 to 60 degrees C This product is not intended for use in potable water systems