Magnaflux 10 Gauss Field Meter, Calibrated Rugged, pocket-size meters used to indicate residual magnetism remaining in part after magnetization. Accurate to +/- 0.5 gauss with scale range of 10-0-10. Certificate of calibration is provided with each meter. Specifications ASME BPVC ASTM E709 ASTM E1444 Part # 505056 Made in UK Quantity: One Piece