Precision machined part, heat treated and Magnafluxed. Applicability – Piper PA12, PA14, PA16, PA18, PA19, PA20, PA22, J5, L-14, L- 18, L-21, AE-1, HE-1. 7/16″ x 20 NF3, fork space 1/4″,Inside diameter 3/8″ , 7/16-20 NF3 thread.