With the JBL Double Stopcock it is quick and easy to remove filters or pumps from the water circuit without draining the whole system. The two stopcocks can be separated in the middle to prevent emptying.JBL Double stopcock with quick coupling+ quick disconnect coupling with stopcock on both sides for easy and quick removal of pumps, filters etc. from the water circuit+ to assemble: cut through the hose, attach the hose ends to the quick release coupling and secure from slipping with lock nuts+ freshwater and marine water resistant, extremely robust POM/ABS plastic, not designed for tap water pressure (4 bar)+ the full water flow is maintained, No reduction in performance when used on technical equipment+ package contents: 1 quick release coupling with stopcocks+ available for hose size 12/16, 16/22 and 19/25