The smallest of Hammerhead's line of knives, including the Cranium, Ulna, Patella, and Ilium. These knives are named after the bone they are meant to be worn closest to. The Cranium, however, is not a strap mounted knife, but it is where you "stab the fish."

Hammerhead's proprietary processes create a very sharp, lightweight and durable knife. The blade is constructed from Stainless Steel, with a hardness of 55-56HRC. The knife is low-profile and designed to be worn close to the body, eliminating “line traps” and minimizing drag.

The “Cranium” is 3.8 mm (0.149”) thick and weighs just 112 g (3.95 oz). At 11 cm (4.33″) in length, it is right-sized for quickly penetrating the skull, while the low profile keeps the knife out of the way until needed.