**broken link removed**. From the description "
Heavy Duty 12V Automotive Relay with Wiring Harness and Socket. These come in a complete set with a 30/40 amp 12 volt relay & 5 wire relay socket wiring harness.
These can be used in a variety of ways but are popular for high amperage applications such as Fuel Pumps, HID Headlights, Strobes, Fog Lights, Stereos, Air Ride Suspensions, Fans, Air Horns, Car Alarms, Remote Starts and so much more. They can be used in conjunction with a switch or using any 12V + or - trigger. A trigger can be anything from the accessory or ignition circuit to a switch which provides a positive or negative trigger. They can even be used with your aux output from your alarm!"
I read this as pretty much anything can trigger the relay and assumed the 30/40 amp was like the ceiling of current it could handle.