Features 1、The focus ring is the best choice for magnifying or altering lenses. It provides a focus system for lenses without a focus system. 2、It can also be used as a macro tube to provide fine focus control for macro photography. 3、Support 10‑15mm/0.4‑0.6in focusing range, provides a 5mm/0.2in adjustable distance for lens focusing. 4、Made of high quality aluminium alloy material, black anodized for longer service life and excellent hand feel. 5、The inner side of the focusing tube is extinction treatment to avoid reflections affecting imaging. 6、Adopted M42 and M39 helicoid interface is universal and easy to transfer. The focusing tube allows the idle old lens to be used for shooting as a digital camera. Specification Condition: 100% brand new Item type: Focusing Helicoid Adapter Material: Aluminium Alloy Color: Black Weight: Approx. 47g/1.7oz Focusing Range: Approx. 10-15mm/0.4-0.6in Interface: Female Mount: M42 Helicoid Mount Male Mount: M39 Helicoid Mount Package List 1 x Focusing Helicoid Adapter