... , and Stable Automatic Compensation 3.Ultra-Short 20cm AT-B Se • Durable, Dependable, High Value Auto Levels All ... AdjustmentsRapid, Stable, and Durable CompensatorThe compensator of AT-B Series incorporates four suspension wires made of super-high-tensile ... (7.9 in.) - Ultra-Short Minimum FocusThe AT-B Series can focus on objects at 20cm (7.9 in.) ... . (1.7kg) Level Topcon Auto Levels AT-B Series