Check the listing for details. НА-3 Precision leveling instrument СБ2. Condition: Used. Listed at 89.99 USD. Plane with autocollimation eyepiece is designed for precise mirror surfaces and for measuring small angular deviations from the mirror plane and a predetermined direction from the vertical position. These tasks are performed by obtaining the image from the autocollimation mirror surface and its reference position on the scale relative to the reticle grid.Essentially AT-3 - It is on-1 without optical micrometer, which usually replaces eyepiece by autocollimation. - Elevation of the telescope - 41.8h; - the field of view when attached to the tube infinity:vertical - 60 ';horizontal - 40 '; - free aperture of the lens - 55 mm;- an increase of the eyepiece - 25.6H;- diameter exit symbol - 1.3mm; - distance of the exit pupil - 6 mm;- the price of grid points - 20 ";- device weight - 5 kg; - weight 5.7 kg drawer; - the tube length - 320 mm; - the height of the device - 200 mm. I sell as a spare part / defective, without spirit level, unknown condition