Fan shroud for the Hexagon Hotend, similar to the E3D Hotend. Uses a 25 x 25 mm cpu fan The profile is small, double check the clearance on your printer's head mount before printing. It's been optimized to use hotend mounts from the VertX extruder http://www.thingiverse.com/thing:137806 NOTE Will not fit on the Hexagon used on the Lulzbot Mini. Lulzbot uses a custom Hexagon heatsink that's smaller (4 fin heatsink) vs the original (8 fin heatsink).Designed to be inserted from the top. The shroud will rest on the top heatsink, preventing it from traveling down towards the heater block.