This works by having different inserts for different door handle types. The main bracket is made from pla, petg…. The adapter inserts are made from semiflexible material. I used Ninja Cheetah filament. The inserts are designed to give a good grip on the handle. I have made the bracket as stiff as possible. The design requires M5 standard allen bolts and screws, length about 20 mm. The bolt heads are recessed and the nuts are captive. This makes installation quick and easy. If necessary it would be easy to make other adapters if the ones I have supplied don't fit your particular requirements. I have made a V2 with the adapter slightly beefed up.