This Auction is for a stainless steel adapter [ DIY Pole Spear Front Mount].
( 1/2" diameter Hole by 6mm -1 Male) Stock OD is 5/8" . Part B2523-20
This 5/8" diameter adapter made to build your own PoleSpear or replace the front fitting of your Pole.
NOTE picture of a Broken Part and a Diver asked me to replace. Picture for reference purpose Only