Ultimate kinetic energy and ultimate penetration. The Easton 4MM FMJ Injexion has been proven day in and day out that it is one of the most extreme hunting arrows in the industry and everyone is talking about them. Utilizing not only the Deep-Six diameter but also the Full Metal Jacket aluminum wrap on the outside of the arrow. This Easton FMJ Deep-Six design helps get the weight up heavy and at the same time allows more of a slick surface resulting in less wind drag and being a lot easier to pull out of targets. Most broadheads in the industry have a Deep-Six option now so there is a huge variety of heads to shoot. See for yourself how crazy good these arrows shoot and how much farther they go into the target. You might even need a new target.