Features: Adopts high quality metal material, lightweight, sturdy and durable. Make various different combinations, which extends the lens focal length for close-up shot and won't alter the optical quality to ensure there is no glare in image. Provides images with better quality than close-up filter, a good substitution to expensive macro lenses for macro photography. Fits tightly onto cameras, and only supports manual operation of focus and exposure. Good accessory for photography lovers. Specification: Condition: 100% Brand New Material: Metal Color: Black Fitment: for Pentax PK Operation: Manual Size(H x Dia): Approx. 6.5 x 6.5cm / 2.5 x 2.5inch Weight: Approx. 113g Packing List: 1 x Extension Tube Ring 1、Adopts high quality metal material, lightweight, sturdy and durable. 2、Make various different combinations, which extends the lens focal length for close-up shot and won't alter the optical quality to ensure there is no glare in image. 3、Provides images with better quality than close-up filter, a good substitution to expensive macro lenses for macro photography. 4、Fits tightly onto cameras, and only supports manual operation of focus and exposure. 5、Good accessory for photography lovers.