Additional compass that can be attached to the gauge Compatible with sub-freezing points, Grip-type bezel equipped with a ratchet function of 5 degrees feed angle; Large side reading window; Magnetic needle balance adjustment for northern hemisphere (NH) for quick and stable operation; Can be installed on CB-206 pressure gauge (sold separately). Add-on compass SK-8 + CB-206 ⇒ CB-500 ● Can be installed with 2 gauge CB-502 (sold separately). Add-on Compass SK-8 + CB-502 ⇒ CB-503