This is the Bueler BU509TD 12 Volt 20/30 Amp Time Delay OFF Relay. It is an SPDT (single pole dual throw) relay.

The new 3rd generation BU509TD Time Delay Relay now has many features installers were asking for. Easy access top of unit, waterproof, 340 degree adjustable potentiometer. The new low 1volt (1k Ohm) trigger voltage gives installers many new uses including stopping "amp pop" noises and even detecting an LED turning on!

Features:

• Standard automotive style relay
• Delay OFF - Adjustable time from 2 sec. to 3 min. with internal potentiometer
• Internal green LED indicates when relay is on
• SPDT - Single Pole Dual Throw
• Can also act like a low voltage relay
• Low 1 volt (1k ohm) trigger voltage
• Power: 12VDC
• Operation Voltage: 8 - 15 Volt DC
• 20 amp / 30 amp rated contacts