This is a mount to attach the Castle Sidewinder esc to the velineon mounting holes on Traxxas cars. It prints perfectly with support material and a slight sanding if its a tight fit. You will need new screws, they are M3 (metric #3) screws about an inch long. i hot glued the on off switch in place and i had to make a slot in the spot where it goes for the wire. (see image) This will work with any of the sidewinders, with or without the fan.