This remix of H3SS's Hot End mount is a groove mount and is lighter and has an integral 25mm fan mount. This item has been used on two types of hot end. Most common a J-Head style Hot End or groove mounted device. The flat edge of this item is to attach a small fan to cool the Hot End barrel. It has two incorporated screw holes for fastening a 25mm fan. Background: The Hot End mount was designed for the Hot End shown in the above pictures and a J-Head groove mount. It can be mounted in various positions (Top, Bottom or elevated.) on a Rostock effector. I mounted my J-Head elevated to provide more print height on my mini-Rostock and to incorporate special design features.