Remove power before adjusting the settings. If this is not done then the changes are not registered by the unit. RS Pro Off Delay Time Delay Relay- 17.5 mm. RS Pro Off delay time delay relay is a dual voltage, single function timer that is compact in size and suitable for DIN Rail mounting. 17.5 mm width DIN Rail mounting Off delay timing function Integrated dual voltage LED indications for power and relay status Wide supply voltage range IP20 (terminals), IP40 (enclosure) protection