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 SVBONY Fully Metal Bracket Base Shoe + 42mm Dovetail UNC 1/4-20 Mounting for Optical Telescope Finderscope An all metal finderscope bracket base for your optical finderscope that comes with the standard quick release dovetail board. It is cambered on the bottom of base. So it can fit and protect the tube very well. Big M4 Screw Large screws are included, which can be adjusted with one hand. It can be used even when wearing gloves. SVBONY Finderscope Bracket Base + Dovetail Board Set Solid all metal construction The body is constructed of high quality materials; sturdy and not easy to damage.