Honeywell 1/4 in NPT Gold Top Automatic Universal Air Vent

2-way on-off low voltage valves consist of an actuator and valve assembly for controlling the flow of hot water. Manual opener (on all models, except straight-through, normally open valves) for valve operation on power failure; valve returns to automatic position when power is restored. All models may be installed without disassembling the valve.|Compact construction for easy installation|Complete powerhead may be removed or replaced without breaking plumbing line connections or draining the system|Actuator motor may be replaced without removing the valve body or draining the system|Patent no. 5,988,201|Light weight|Proven durability|Easy to install|No clog vent|360 degree adjustable collar ring for installation flexibility|Stainless steel concentrator which eliminates gurgling noise