Topcon offers a wide range of automatic levels for
the land surveyor, civil engineer and contractor. All AT-G series
levels feature a magnetically-dampened compensator hung by four
special mylar ribbons having superior resistance to cold, heat
and shock. The AT-G1 model features a 360° glass horizontal circle
using a 25x magnification microscope to read the circle, while
the AT-G2 thru AT-G7 have a standard 360° horizontal circle. All
models are waterproof with a nitrogen gas sealed telescope which
prevents clouding and moisture on the lens.