Minelab Lithium Ion Battery with Built-In Amplifier.
The GPX isn't exactly a lightweight gold detector. The new lightweight Lithium Ion battery for the GPX is half the size of the standard battery. The Li-ion makes longer nugget hunting trips much easier and with less arm fatigue.
Compatible with Minelab GPX 4500, GPX 4800, and GPX 5000.
BATT, ASSY 7V2 2A5h LI ION GPX