I printed this with Ninjatek Cheetah TPU material. It has a 95 shore A durometer and works well on my Mendelmax. You could also print with ninjaflex or any other flexible material. I made them so I could raise up the motors on my Aurora 90 to move the props up away from the aluminum duct supports. The mounts are 2.5mm tall, which will require you to use longer 2mm screws. The stock screws are too short with these spacers.