This is the JBL 786XHD 5/16" Extra Heavy Duty Slide Ring Warhead Slide Ring
Fits JBL Spear Guns with 5/16" (8mm) Shaft and Warhead Spear Tip
17-4 Spring Stainless Steel
Diameter: 5/16" (8mm)
Prevent Loss of Spear Tip
Adds Shock Absorption
Slide ring is made for use with the JBL Spear Guns equipped with the warhead spear tip.