This throttle wraps around the Rad Runner's rotating throttle and is secured in place with an M3 screw. There are ridges to help the band bite into the rubber throttle, but you can add rubber pads or a strip of neoprene or dip the band in Plasti-dip to improve its grip.
Increase perimeters to 3 or 4 to ensure the band is strong and resistant to overtightening. ABS and PETG are likely to last longer, but PLA works fine.
The author hasn't provided the model origin yet.