Part Type:HVAC Zoning Dampers Part Number:NSPRD024-6NC Colour: Silver Material: metal 6inch power open, spring close, damper is easily convertible to a power close, spring open damper for direct control from a zone control system, and can also be used as a fresh air damper or can be controlled by a thermostat or switch.This means you will not ever get stuck with the wrong configuration - use this damper in the "normally closed" mode when connected straight to a thermostat or a switch, later easily convert it to "normally open" if connecting it to a zone control system.Voltage is 24 volts AC, with convenient two-wire operation Package Contents: 1x HVAC Zoning Dampers Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.