2.0,3.0,2.5,3.5，4.0,5.0,5.5, 6.0,7.0, 8.0mm...These bullet connectors are gold plated to ensure the best possible connection,Use these bullet connectors to connect two rc parts that you want to be able to disconnect easily.You will need to solder on a wire to one end of  bullet connector. In some instances it is recommended to surround the exposed ends of the bullet connectors with heatshrink tubing. We sell solder, wire and heat shrink also.