Almost all transmitter power packs today are made using NiMH cells. Many users have noted the much higher capacity or lighter weight of Lipo cells, but LiPo have voltage "too high" (3.7V/cell) to work reliably with most transmitters, receivers, and servos.
But unlike LiPo, LiFePO4 cells (3.3V/cell) can be an excellent replacement for NiMH on voltage basis. And compared to high-capacity NiMH packs,BUFFALO LifePO4 Radio batteries have these other advantages:
+More capacity per gram, meaning longer transmitter duration between charges
+Almost no "self discharge", so your radio is always ready to go even weeks after charging.
+Faster charge time