It prevents the zoom from pulling on the turret plate and damaging/warping it. It screws into the hole on the turret plate as shown in photos.
Bolex Door And Finder For Bolex H16 Non Reflex Cameras Bolex
Hyper-Kern-Paillard 0.5x Accessory Lens for D-Mount Bolex Lenses w/Case + Caps
Bolex hand grip for Bolex H16 Reflex camera RX3 RX4 RX5 No Adapter Plate
Easy Installation Locking Casters Locking Mechanism Quick Installation
2x Locking Casters Easy to Install 70360 Lawn Wheel Locking Mechanism Spare
2 Pieces Locking Casters Grill Caster Wheels 70360 Garden Patio Wheel Locking
