CMD534351 Red Insulated Crimp Receptacle, 6.3 x 0.8mm, 0.5mm? to 1.5mm?. Female crimp receptacles are a type of electrical wiring connector which, when mated with a male tab connector (or male quick disconnect), provide a fast and reliable interconnect between two wires. The body of the connector is made from tin plated brass and features an additional internal copper sleeve. This copper sleeve strengthens the barrel and provides a robust and secure crimp.