You may be most familiar with them from Nitro Funny Cars

Center and Threaded Spring Retainer for King Offroad Shocks (Z-S1282)

New shock design and soft shock spring setup with 12mm big bore shocks

and they may also be attached to a Modeler's Knife (Item 74040)

Chassis Type: FM-A

Power Hobby - Professional Electric Power Driver Drill Machine, RC Tools Paint & Supplies Aerosol Paint You may be most familiarComfortable handle and easy to use buttons. A USB C type charge port ( USB included ) Specifications: Voltage: 3. 6V Chuck Size: 0. 25" (6. 35mm) Speed (no load): 220rpm Max Torque: 5Nm (0. 73ft lb) Dimensions: 5. 39x1. 29" (137x33mm) Charge Port: USB C type Weight: 142g (5. 0oz)