This mandrel can be installed on the Ruger Moon Clip Loading Tool (#18751) to simplify loading and unloading of rounds in the moon clip. It is made of aluminum and is .390” in diameter. This mandrel is designed for use with TK™ Custom Moon Clips (#18730) and Ruger Moon Clips (#90516) for the Ruger SP101, 9mm, 5-round. Made in the USA by TK™ Custom.