COLLEGE PATTERN Tube Diameter : 25mm (1”) Achromatic : 25mm (1”) Objective Dia Focal length of : 178mm (7”) Achromatic Obj. Ramsden Eyepiece : 10x Cross wire : Fine Quality Cross line Graticule . Base : Heavy Metallic Painted Base with Three Leveling Screws Supporting Rod : 15mm (5/8”) Telescope Tubes : Both tubes are of heavy gauge of Brass material Focus : By Smooth Rack And Pinion (Appr. 2” motion) Supplied with Perspex scale and scale holder.