To use these 1x12-pin crimp connector housings, first take one of the pre - crimped wires from your set. Insert the wire with the pre - crimped terminal into the housing. Make sure it fits snugly. Once all the wires are in place, your custom cable is ready to connect to male or female headers or solderless breadboards. When handling these housings, be gentle to avoid any damage to the pins. Store them in a dry place away from dust and moisture. If you notice any dirt on the housings, you can use a dry cloth to gently wipe them clean.