... 4:1 SQF-LII is a new modal of stereo zoom microscope. The ratio is 4:1,can be widely used ... medical service, geology archaeology and biology as well. The binocular observation tube is inclined in to 45 degree. The head ... 5.These made the observation very comfortable. The two zoom control rings at both side of the head and their ... . When you use halogen, the brightness is adjustable. zoom stereo microscope