1,M42 Thread: This telescope tube adapter ring has a thread of M42x0.75 and is suitable for camera T2 mount lenses. 2,Height Adjustment Valve: The M42 thread telescope Sleeve has a height adjustment valve to adjust the height of the eyepiece: 67mm to 80mm. 3,Diameter Adjustment Valve: The telescope sleeve has a diameter adjustment valve that allows you to adjust the diameter of the eyepiece from 45mm to 45mm. 4,Easy to Install: Camera telescope tube with hollow design, does not affect the focus wheel, simple and practical, easy to install. 5,Scope of Application: The M42 thread telescope tube is suitable for birdwatching, SLR micro single cameras and helps visual photography. 1 x M42 Thread Telescope Sleeve Item Type: M42 Thread Telescope SleeveMaterial: Aluminum AlloyThread: Male Thread: M42x 0.75mm/ 0.03inScope of Application: Birdwatching Telescope, SLR Micro Single Cameras Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.