Camera Accessories
Fotodiox Pro Premium-grade Tripod Lens Collar for Canon EOS EF 100mm f/2.8L Macro IS USM Lens, as Canon Tripod Mount Ring
Aluminum die casted creating a tripod mount that is Lightweight, strong, and affordable All metal construction Replaces Canon Tripod Mount Ring D Includes a 24 Month Manufacturer Warranty
https://www.bizrate.co.uk/cameraaccessories/fotodiox-pro-premium-grade-tripod-lens-oid6611070369.html