This is a  brand new Cox .049 .051 Tee Dee High Compression, High Performance Glow Plug with identifying knurl. YOU GET 1 PLUG and copper gasket.  This is the original equipment used on the Cox .049 & .051 Tee Dee, Venom and Killer Bee engines. These are Made in U.S.A by MECOA K&B Mfg Cox part number 1702 --- MECOA part number 911-950 GLOW PLUGS USE 1½ VOLTS If you exceed 2 volts, you will burn out the plug. This will be your fault, not ours. If you not sure of what you are doing, DON'T DO IT. Contact us