Ring on Twitter: "Get in touch with us before before the frustration sets in. Most of the time, any issue is easy to fix on our end. http://t.co/Lv7ytPNG9q" / Twitter
Lens Collar Tripod Mount Ring Support Holder for Canon RF 70-200 f/4L IS USM | eBay
X1 Support Ring Round Flat Bottom 20mm Light Silver: SB0044 - Etsy