• 1.This ring tripod is specially designed for Canon lens compatible EF 100mm f/2.8L Macro IS USM Lens. Not for use with EF 100mm f/2.8 USM Macro Lens • 2. Original factory standard, split structure. Original factory standard, split construction. Redesigned based on the old TMR ring using new technology and new materials • 3. The inner diameter of this tripod ring is about 68mm. The lens contact surface adopts a flocking surface, the width of this contact surface is 18mm. Net weight is about 142g • 4. The bottom of the lens tripod collar has a 55mm Arca Fit Quick Release Plate feature, which can be used directly with 39mm Arca-Swiss Fit tripod ball head, panoramic head and clamp. More practical than other tripod rings without quick release plates. We also reserved a 1/4" screw hole for securing the lens directly to the tripod and stainless steel anti-skid screws • 5. This ring tripod is made of high quality aviation aluminum, lightweight and sturdy. World class high end CNC turning center, surface anodized for precision machining. The appearance and exquisite workmanship is much better than similar products made in molds