Canon EF 2X III Extender Product Specification Lens construction (elements/groups) 9/5 Dust/moisture resistance Yes? Max. diameter x length (mm) 72.0 x 52.7 Weight (g) 325 Soft case LP811 Dust/moisture resistance ? Lenses with dust/moisture resistance are fitted with a rubber ring on the lens mount which may cause sligth abrasion of the camera mount. This in no way affects either the lens or camera performance.