Universal Donut Adapter Ring (for 80mm & under lenses)
Opteka MB-X Pro Metal Matte Box Kit with Universal Lens Donut Set for All Camera Rigs with 15mm Rod Systems - Walmart.com
Cavision 3 x 3" Matte Box Kit with Donut, MB3485S-15RSA-DSLR-M
Lanparte Universal Matte Box Rubber Donuts For 60-85mm Camera Lens - Photo Studio Kits - AliExpress
114mm Threaded Donut Rings - Bright Tangerine
Photography and Cinema · MAX-D Matte Box Donut
Vocas MB-436 kit: for any camera with 15 mm rail support (incl. SA and donut adapter ring) — Take One Film & Video
UMB-1 Universal Mattebox (Universal Donut) — Wooden Camera
Wooden Camera UMB-1 Universal Matte Box Cloth Donut 204900 B&H
Movo MB400 MK II Professional Matte Box with Swing-Away Arm. French Flags, Side Wings & Universal Anti-Reflection Donut (for 15mm Rod System) - Walmart.com
Movcam 144mm Universal Stretch Donut for MM1, MM1A and MM102 Mattebox MOV-301-0201MM1
Amazon.com : SmallRig Rubber Donut for Lenses with 58-114 Diameter, with Rear Opening for SmallRig Light Matte Box - 3409 : Electronics
SmallRig Silicone Donut with 114mm Rear Opening for Matte Box 3409