Custom adapter tapered. This adapter has SnakeClamp 3/8"-24 male threads on one end and a 3mm diameter pilot hole on the other. The barrel is 30mm long and has an outside diameter of 18mm tapering down to 13mm. We will thread the other end to your specifications. 7 day lead time, free domestic shipping via First Class Mail. This item will ship separately from a different location. PLEASE SPECIFY THREAD SIZE AND DEPTH IN ORDER CHECKOUT NOTES.