Note: The thread pitch of this M42 mount is 1mm. All the threads with a pitch of 0.75mm are T2 mounts used for astronomical telescopes/retroreflectors, not this product. Function: It can be used as a photography focusing tube accessory, can also be used for macro photography, and can also be used as an extension accessory for other M42 products. Parts, suitable for players to DIY modification, the specific effect needs to be practiced Color: Black Material: aluminum alloy Package Contents: 11 * extension tube Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.