1、The tripod mount ring is designed for Canon EF 100mm f / 2.8L Macro IS USM lens, It cannot be used for Canon EF 100mm f / 2.8 USM macro lens. 2、Adopt original factory standard, split structure. It is based on the old version of the tripod mount ring, redesigned and produced using new materials and technologies. 3、The inner diameter of the tripod ring is about 68mm/2.7in. Thick flocking is attached to the surface in contact with the lens, the width of the contact surface is 18mm/0.7in. 4、The bottom of the tripod mount ring adds Arca 55mm length for quick release plate function, can be used fo Arca-swiss39mm tripod ballhead, panoramic heads and clip. Reserved 1/4'' screw hole and stainless steel anti-slip screws to fix the lens directly on tripod. 5、The tripod mounting ring is made of high-quality aviation aluminum, lightweight and strong, and processed with high precision. CNC turning center, anodized surface, superb appearance and craftsmanship. 6、The bottom of the lens mount ring adds for Arca-Swiss 39 mm lengt fitted quick release plate function, compatible for RRS / ARCA-SWISS / PMG / WIMBERLEY / MARKINS / PHOTOCLAM / SUNWAYFOTO / BENRO / SIRUI / MARSACE / ISHOT's Arca 39 mm fitted ballhead, suitable for iShoot IS-JZ30 / IS-JZ50 / IS-JZ64 / IS-QJ58 / IS-QJ64-FD / IS-JZ60BK / IS-JZ70MFT / IS-JZ80BK. Condition: 100% Brand New Item Type: Lens Tripod Mount Ring Model: IS-C100L(Can replace IS-TMR) Material: aluminium alloy Color: As picture shown Weight: Approx. 192g Fitment: fit for Canon EF 100mm F2.8L Macro IS USM lens 1 x Lens Tripod Mount Ring