Easy setup. All you need is a 3/4 inch (19mm) hole and the switch will sit in nicely;no more square cut outs. Our switch comes with a kyhole slot to prevent unwanted rotation SPST 2 pole design (On/Off) 3rd poles with LED to be connected to earth. Functions: It can be applied as the switches for the additional electronical equipment inside&outside the car.(such as flashing lights,chassis lights,and dome lights) Condition: Color: Black and Blue Material: plastic Light color: Blue LED light Size: 2.3*2.5cm Quantity: 1 pc Rating: DC 12V 20A Type: 3 Pins SPST: ON-OFF Note: 1. Instruction is not included,professional installation is highly recommended. 2. Please check the size measurement chart carefully before making payment. Package Contents: 5pcs Blue LED light Round Switch(waterproof) Only the above package content, other products are not included. Note: Light 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.