3-prong wiresPlug in and use. No need to solder. Red wire - VCC (RAMPS), Black wire - GND (RAMPS -), Green wire - SIGNAL (RAMPS S). Reliable DesignLimit sensor using 22AWG wire, the copper wire inside is thick and can withstand 2A current, 300V voltage. Easy InstallationMechanical stopper triggered by a simple mechanical switch. the other side of the plug to make a whole, can be inserted directly to use. Wide UsageLimit switch is for RepRap 3D printer or CNC machine, it is supported by RepRap electronics, RAMPS 1.4 and by other popular RepRap boards. Package Contents6 x 3d printer limit switch.Features: Plug- and-use Mechanical Stop Switch with LED Indicators. The cable is 22AWG wire, the inner copper wire is thicker than ordinary wire, can withstand 2A current, 300V voltage . The insulation layer has a wide temperature range of up to 80 degrees. The connection cable is not easy to break, and plugging and unplugging is also convenient. is for RepRap 3D printers or CNC machines, it is supported by RepRap electronics, RAMPS 1.4 and other popular RepRap boards . Specifications: Wire Type: 22AWG Working Voltage / Current: 300V / 2A Resistance to temperature: 80 degrees centigrade Cable length: 70cm Size: 40 x 15mm Tips: Under normal circumstances, the system should be configured for at least three mechanical switches. Connection Description: Red wire - VCC (RAMPS) Black wire - GND (RAMPS -)< /p> Green Wire - SIGNAL (RAMPS S) Package Contents: 6 * Limit Switch 6 * 3Pin Cable 70cm