Working in a sprinkler trench is tough enough-don't make it harder by using traditional pipe fitting methods that require hot, toxic glue, clamps or frustrating barbed fittings. Hydro-Rain offers a better way: blu-lock. Everything you do from the valve out, you can now do faster & easier with blu-lock. Primer? glue? clamps? tools? with the blue-lock system, you don't need them! simply stated, blu-lock by Hydro-Rain is the fastest, greenest, irrigation installation method in the world. Blu-lock is for non-constant pressure, valve-out, cold water, outdoor direct burial irrigation connections only.