** TwistSeal Deluxe (55 mm) Supply / Return Modules c/w Heavy Duty Zone Valve Supply & Balancing Return (pair)
The supply module provides on/off manual control to allow isolation of individual loops, and may be fitted for electric actuator and thermostat operation. The return module permits the balancing of the flow rate. Comes with O-rings. Modules can be locked in place with a couple of turns. No threaded rod, solder, or tools required. Just twist and seal.