C7 sockets SPT-1 are great for doing repairs on broken C7 Christmas lights. C7 sockets are also great for making custom Christmas light strings allowing you to make your own spacing between bulbs. We sell both C7 sockets in SPT-1 and SPT-2 wire to help with those custom stringers. Be sure to match C7 sockets to your SPT type wire. " Example" If using SPT1 wire be sure to use a C7 sockets SPT-1 type socket.