Mount for attaching a cooling fan to the RigidBot extruder and a couple of optional fan nozzles. The fan clips into a hinge and can be tilted up for easier nozzle access. I made the extra nozzles to experiment with. I used the following 24v fan at Amazon (the wire polarity needs to be switched so check that before plugging it in). It seems to be a common part and can probably be found at other places for less. For the upper right fan hole, I used a 6-32 flathead machine screw, but other options will work as it threads into the plastic. I use a 1/8" build plate so the fan is designed to clear the clips. If you're not using a build plate, the fan probably may not clear the bed leveling screws (I haven't tried that configuration). I would recommend turning down the default fan speed, I've noticed that having it too high can reduce the nozzle temperature significantly below what the thermistor reports, especially when using one of the fan ducts.