Heat toughened 7mm stainless steel shafts with 3 tabs (fins) suitable for open muzzle spearguns.  These tabs are also small enough to use through some closed muzzles or muzzles modified to suit.

Heat toughened 7mm stainless steel shafts with 2 slots (notches) suitable for open & closed muzzle spearguns.

Heat toughened 7mm steel shafts with 2 notches suitable for open & closed muzzle spearguns.