This JBL front portion shaft is for the Travel Magnum and Travel Magnum Combo Spear Guns. The JBL7427S is 27" (686 mm) long with a 5/16" (8 mm) diameter and 6 mm threads. Having spare parts for your gun or sling is the only way to assure you won't get skunked on a spear fishing trip. Constructed of corrosion resistant 17-4 (spring) stainless each shaft is hand-tuned for alignment then heat-treated for maximum hardness to reduce flex and provide optimum energy transfer. Spear Shaft makes a great Save-A-Dive Kit item.