1. It has a wide range of functions. CAR Emergency Hazard Warning Flash Light switch 2. For load under 3 Amp, you do not need a relay with this switch. For load above 3 Amps, we advice you to use of Automotive Relay. 3. Easy setup. All you need is a 5/8inch hole and the switch will sit in nicely. 4. LED on all the time or only when switch is on(depending how you wire it) Hole size required 16mm 5/8inch Led Power Switch latching type:ON/OFF LED voltage: 12V only Operation Type: Latching Depth inc contacts 35mm Colour: silver Material: metal Package Contents: 1 x Car Emergency Flash Light switch Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.