Focus with Scale The front part focuser with scale for easy and repeatable focusing Lock Ring Locking ring can ensure that the focus position does not change during use Six-point guide ring The six-point fixed method with adjustable angle can adjust the coaxiality between the guide mirror and the main telescope according to the needs; the six screws are equipped with nuts to ensure that the screws will not loosen during use M42 thread T ring is connected by standard M42 thread, suitable for all standard telescope camera AR-coated protective window to maximize transmission and protect the sensor. SV905C telescope camera is better for ‘lucky imaging' of planets, double stars, and other compact objects, especially for telescopes with longer focal lengths. Standard thread size SV905C telescope camera adopts a diameter of 1.25 inches, which can adapt to different focal length guide lenses and OAG guide stars. The internal thread is M28.5X0.6.