FG sensors 3 axis fluxgate magnetometers comes in three variants: 

 

FG4 - 3 axis OEM fluxgate sensor that comes in a small, lightweight, and waterproof package with three separated frequency outputs for each axis.

 

FG43 or FG33 are both out of the box, 3 axis fluxgate sensor that provides measurement results over the UART interface and comes with optional GPS and automatic SD card data logger. Main difference between both is that FG33 variant comes in waterproof enclosure.