Based on this product's specifications, here are some alternatives and similar models
Filter step-down adapter B&W 49–46mm (1102858) — for mounting 46mm accessories on 49mm lenses
Summary description:
Step-down filter adapter B&W model 1102858 converts a 49mm lens thread to 46mm, enabling attachment of 46mm filters, lens caps or other accessories to lenses with a 49mm front thread. Made for practical use when matching accessory sizes, it offers a compact metal construction and simple screw-on installation suitable for photography and videography workflows.