This is a replacement joystick knob for a large variety of different powerchairs. The hole is 1/4″ in diameter; however, if you need a different hole diameter, please let contact us. There are dual tightening screws to help secure the joystick. We can confirm fitment on the following models; however, you should still measure the joystick shaft to make sure it is ¼” before ordering. Permobil F3, Permobil F3 Corpus, Permobil F5, Permobil Koala, Permobil M3, Permobil M3 Corpus, Permobil M5, Permobil M300, Permobil 300, Quantum 3, Quantum Edge 3, Quantum Q6, Quantum Q6 Edge, Quantum Q6 Edge 2.0, Quantum Edge 2.0, Quantum Stretto Q-Logic 3, Quickie 646, Quickie 636, Jazzy Passport, Jazzy 7, Jazzy HD, Terra/Terra SX B+B Enjoy Mobility, Air Hawk Power Chair, Alltrack HD/HD3, Vive Mobility Foldable Long Range Transport Aid, MobilityPlus+ Ultra-Light, Invacare TDX SP, Scewo Bro, Fold&Go MagshockThis was heavily remixed from a model created by Thingiverse user trailogy, and is licensed under cc-sa. Skull by trailogy on Thingiverse: https://www.thingiverse.com/thing:518109 They can be printed with a smooth or textured finish. The textured skulls are easier to grip. I can custom make all kinds of joysticks, if you would like something made please message me.