WOLLENSAK 2.5" F 1.6 SUNRAY 16MM PROJECTOR LENS WITH STANDARD 30 MM BARREL SIZE | eBay
Know Your Lens Barrel (1): Useful Marks, Rings, and Switches
Goerz Dagor 14" (355mm) f7.7 Large Format Lens in Barrel. Covers up to 12x20. | eBay
Lens-mounting method is drop-in simple, yet machine-centering accurate | Laser Focus World
Lens Barrel | Paras Defence & Space Technologies Ltd.
A Novel Barrel Design of a Light Weight Camera for a Remote Sensing Satellite | SpringerLink
Broken lens barrels; repair might be DIYable: Canon SLR Lens Talk Forum: Digital Photography Review
Custom Precision OEM Service Aluminium CNC Turning Machining Camera Lens Barrel Rings Parts Sp-127 - China Optical Parts, CNC Machining Part | Made-in-China.com