"AC Close-up Lens" is a close-up photography accessory that allows for close-up shooting. This is a high-quality close-up lens that corrects chromatic aberration with a 2-element, 1-group design. Compared to single-element types, it exhibits superior descriptive power, resulting in sharp images. Combining two lenses allows for even closer shooting. For example, combining No. 2 and No. 3 allows you to use it as a No. 5. Lens Configuration: 2 elements in 1 group Focal Length: 330mm Filter Diameter: 52mm