Watts LFA-5 Compression Cap, 1/4-Inch This compression fitting is easy to use for both contractors and the do-it-yourselfer Durable, lead-free brass is an excellent choice, with all threads manufactured to highest quality standards and tolerances Easy to use for contractors and homeowners For use with copper, brass, aluminum, and plastic tubing Lead-free brass is not more than a weighted average of 0.25% lead when used with respect to the wetted surfaces of pipes and pipe and plumbing fittings and fixtures