Ring diameter inside : 68.5mm Ring breadth: 17.8mm Ring thickness: 6.1mm Color: black Material: plastics(ABS) Description: * Color: black * Material: plastics(ABS) * The UNC (Unified National Coarse Thread) is 1/4 * Suitable For Canon EF 100mm f/2.8L Macro IS USM LENS Package contents: 1x Tripod Mount Ring D