Use this shaft for your spearfishing and you wont have to worry about functionality or aging. It is made with 17-4PH Tahitian tempered stainless steel, which prevents corrosion, resists bending and is lightweight to reduce drag. Made with three special high resistance pins and one lower embedded barb.Materials: 17-4PH Tahitian hardened stainless steelDiameter: 6 1/2mm.Barbs: One lower embeddedPins: Three special high resistanceWarranty: Two year limited