TCN Auto Level AT-B Telescope 24-32mmRapid, stable, durable compensator The compensator of AT B Series incorporates four suspension wires made of super high tensile metal, which features minimal thermal expansion coefficient, providing unmatched durability and accuracy. The finely tuned magnetic damping system quickly levels and stabilizes the line of sight despite the fine vibrations present when working near heavy equipment or busy roadways. Horizontal circle for measurement Horizontal