The Evolution RO1000 and Merlin Garden Pro Electronic Shut-Off Kit (HydroLogic 27005) includes a mechanical float valve, solenoid with 1/2-inch quick-connect fittings, electric float switch and transformer. Quick Connect fittings make installation easy and mess-free. Save resources by shutting off water flow with greater accuracy. Fill any tank or reservoir unattended, without any more potential flooding or water damage. The HydroLogic Electronic shut-off kit fits standard 1/2-inch water lines. Helps to customize your indoor hydroponic or outdoor garden. Keeps water at the appropriate level. Eco-friendly choice.