Endstop V1.2 mechanical limit switch module with cable RAMPS 1.4 for 3D printer4 interfaces:SIG,two GND and VCC ;With 1m lead line;With LED indicator;Fixed installation pitch is 18.7mm.Feature:These microswitches have three connectors:COM = common: wire to signal on your electronicsNC = normally closed: wire to ground on you electronicsNO = normally open: not required