Our Tuna Spike is CNC machined out of 316 Marine Grade Stainless Steel with an Anodized 6061 Aluminum Handle. The spike is threaded and epoxied to the handle ensuring that the spike will never twist or fall apart over time. This tool is designed to spike quickly and directly into the brain of a fish, causing immediate brain death. A fish brain is usually located slightly behind and above the eye. When spiked correctly, the fish fins flare and the fish relaxes, immediately ceasing all motion. The blood contained in the fish flesh retracts to the gut cavity, which produces a better colored and flavored fillet.