The Parker Hannifin 71908 5/8" Fast-Tite Compression Style Plastic Fitting for Pulsar® 4 Pool System is a compression-style fitting that installs in seconds without tools and provides a tight, sure, leak proof seal without clamps or adjustments. A unique grab ring for tube retention, coupled with a nitrile o-ring, creates a positive seal and assures good tube retention with only hand tight assembly. This product is designed for use with soft metal, glass tubing and compatible pool maintenance systems.