Custom adapter. This adapter has SnakeClamp 3/8"-24 male threads on one end and a 6mm diameter pilot hole on the other. The outside diameter is 18mm and the barrel length is 38mm. 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.