1oz HELIMAX-XP Camera Telescope Optical Instrument Focusing Helicoid Grease PTFE

New Handmade Plastic PVC - Focusing Card for Pentax 17 Camera (2 Pack)

M42 M52 M58 M62 to M65 Thread Ring Adapter for Lens Focusing Helicoids Tube 65mm

Optical Glass Optional LED Plano-convex Lens DIY Focusing Condenser Lens 28-40mm

M42 M52 M58 M62 to M65 Thread Ring Adapter for Lens Focusing Helicoids Tube 65mm

New Handmade Plastic PVC - Focusing Card for Pentax 17 Camera (2 Pack) White

4 Way Macro Focusing Rail Slider with Quick Release Plate 1/4 Screw Hole for Clo

Lens Modification M42 to Sony E Mount Adapter for Camera Focusing Helicoids Tube