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 Use the SV221 zenith mirror to obtain an upright image and an upside-down image. With a brass pressure ring The SV221 diagonal mirror can protect the eyepiece from being scratched and not damage the service life of the eyepiece. Large screw design Easy to use, locking eyepiece installation is easier and more stable. With filter thread The SV221 diagonal mirror has M28.5x0.6mm thread, standard thread size, you can install 1.25 inch filter.