12 Volt, 30 amp RELAY, takes high amp voltage from the battery direct to the cell, while the voltage to your dash switch can be low-amps with no need for heavy wires, or burning up the switch with too much amperage. You can Download wiring instructions after you order by logging on to our website with the user name and password you provided. *Also note, for shipping of product under 1 lb. select USPS for shipping. We are close to the post office. Thank you.