Height and Diameter Adjusting Valve: The height of eyepiece can be adjusted from 67mm to 80mm. The diameter of eyepiece can be adjusted from 41.5mm to 44.5mm. Hollow Design: This T mount spotting scope camera adapter tubee adopts hollow design, which does not affect the focusing wheel and the adjustment of the focusing hand wheel on both sides. Easy to Install: This photographic accessory is simple, practical and easy to install, made of aluminum alloy and can be used for a long time. Applicable Scenes: This adapter tube and T ring is suitable for birdwatching spotting scope and SLR camera, which is helpful for visual photography. Applicable Model: This adapter cylinder thread M42x0.75 is suitable for T2 mount lens of camera, and T2 adapter ring is applicable to for Pentax K series SLR camera.