M42 to M42 Mount Adjustable Focusing Helicoid Macro Tube Adapter - 25mm to 55mm The all-metal adapter is designed to fit the lens securely, yet can be removed when not needed. Introduction: This tube is useful for lenses without a focusing ring. It can also be used as a macro extension tube. There is no electronics in the adapter, and focusing must be controlled manually. Color: Black Material: Aluminum Alloy Made of anodized aluminum with a black finish and high quality. The length of this helicoid tube ranges from 25mm (min) to 55mm (max), offering a 30mm movement distance for lens focusing. You can use lenses with an M42 screw mount, such as or 42mm screw mount lenses, and even magnification lenses. This helicoid tube is useful for lenses that lack a focusing ring. The tube provides fine focusing control for macro photography. This focusing helicoid tube is manufactured with a 42mm front mount and a standard 42mm rear mount, and is constructed from lightweight alloy. It can be used as a macro cylinder. Automatic aperture and autofocus will not function correctly when using this adapter. Manual focusing with exposure metering is fine with the adapter. Compatible with: M42 lenses and cameras. Package includes: 1 X M42 to M42 Mount Adjustable Focusing Helicoid Macro Tube Adapter - 25mm to 55mm Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture to look slightly different from the real thing. The allowed measurement error is +/- 1-3cm.