NiSi Filter Adapter for Ricoh GR III (49mm) NISI-RGR3-AD-49 B&H
Jagg 4700 Offset Oil Filter Adapter with Thermostat for H-D Twin-Cam – Jagg Oil Coolers
CONTINENTAL OIL FILTER ADAPTER | Tempest Plus
This hinged-lens filter adapter protects your lenses
Amazon.com : K&F Concept 18 Pieces Filter Ring Adapter Set, Camera Lens Filter Metal Stepping Rings Kit (Includes 9pcs Step Up Ring Set + 9pcs Step Down Ring Set) Black : Electronics