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 .510” in diameter. This mandrel is designed for use with TK™ Custom Moon Clips (#18737) and Ruger Moon Clips (#90515) for the Ruger Super Redhawk, 10mm, 6-round. Note: 90515 Moon Clips may have a small burr inside of the center that must be removed to utilize the mandrel and loading tool. Made in the USA by TK™ Custom.