Smallrig
Accessory Thumb-Wheel-Lock-Nut-877
- Wheel Lock Nut
- 1/4" Female thread
- Lock Nut
- For Maigic Arms and Ball heads

Thumb-Wheel-Lock-Nut-877
Thumb Wheel Lock Nut 2pcs pack
Center 1/4" screw hole
It features a standard 1/4" hole that can be used in articulating arms or shoe mounts with 1/4" screws. It is lightweight, durable and compact.
Source: https://www.smallrig.com/smallrig-thumb-wheel-lock-nut-2pcs-pack-877.html