Fuhjythy M42 To M42 Focusing Helicoid Ring Adapter 12-17Mm Macro Extension Tube(1Pcs)

This focusing helicoid tube is made with standard M42 mount and is made with light-weight alloy. Made of Anodized Aluminum in Black finish with high quality. The length of this tube is 12mm(min) to 17mm(max),it offers a total of 5mm movement distance for the lens focusing. This tube is useful for those lenses without focus ring offers fine focus control for macro photography. You can use M42 screw mount lenses, such as or 42mm screw mount lenses, and even enlarger lenses.