Specification: Colour: Black Voltage: 12V Current: 40A Contact Type: SPST Material: Metal, Plastic Pin Number: 4 Pin Note:The Contacts on this relay is normally open (NO) Features: - new - SPST contact type - Durable - 12V DC rated voltage - It is used when a device draws heavy amperage such as car alarms, remote starts, HID headlights, pop doors, trunk releases strobe lights, fog lights, stereos, fans, air horns, and much more. Note: 1. Please check the size measurement chart carefully before making payment. 2. Please allow 0.5-1 inch difference due to manual measurement.(1 inch=2.54cm) 3. The color of the actual items may slightly different from the listing images due to different computer screen, thanks for your understanding. 4. Instruction is not included. Package included: 1 x Car Relay with Socket