Grade 2C50 is a 4 wire pencil fit flush contact designed to meet the requirements of Security Grade 2.Of the 4 available wires, two carry the signal from the switch while the remaining two function as a tamper loop.This variant is flanged.The C series of contacts are designed to have a small form factor and easy push fit installation. They are ideal for use on windows or anywhere a standard 20mm recess will not work.