Tamron
The Digital Optics 2.0x Pro High Definition lens with a Canon 46.5mm to 52mm step-up/adapter ring is an auxiliary telephoto conversion lens that screws onto the front filter threads of a compatible camera or video lens to double its focal length.
Overview & Specifications:
Magnification: 2.0x telephoto multiplier (doubles your focal length, e.g., turning a 50mm lens into a 100mm equivalent).
Adapter / Thread Size: Includes a Canon-branded adapter/step ring converting from 46.5mm to 52mm filter threads.
Design: High-definition optical glass in a metal housing, labeled "Digital Optics Japan".
Application: Typically used on vintage camcorders, bridge cameras, or standard DSLR lenses featuring matching front filter thread diameters.