M42 to M42 Mount Focusing Helicoid Ring Adapter 17 - 31mm Macro Extension Tube

Description:
* This focusing Helicoid tube is made with standard M42 mount and is made with light-weight alloy. Both ends are 42mm.
* This Helicoid tube is useful for those lenses without focus ring. It could be used as Macro barrel, and offers fine focus control for macro photography.
* The length of this Helicoid tube 17mm (min) to 31mm (max), it offers a total of 14mm movement distance for lens focusing.
* User can use it with M42 screw mount lenses, such as Carl Zeiss, and even enlarger lenses.
* Very useful for enlarge lens, some of them are Leica 39mm / M39 / L39 mount. You may need an additional 39mm-42mm adapter if you want to use 39mm enlarge lens with the Helicoid tube.
* This tube useful for lens without focusing ring. And it can be use as macro extension tube. There is no electronic element in the adapter, aperture and focusing must be manually control.

Package contents:
* 1 x focusing helicoid