The Mag669 from Bartington Instruments is a Magnetometer with Mass 200 gms(Sensor Head), 15 gms(Electronics), Measurement Range ±75 µT, Linearity 0.0015%, Frequency Response DC to 100 Hz, Supply Voltage 15 V. Tags: Three Axis Magnetometer, Fluxgate Magnetometer. More details for Mag669 can be seen below.