Trend AIR/P/4 3.6V 3.5Ah Ni-MH 8 hour replacement battery for the Trend Airshield Pro.
The AIR/P/4 uses Ni-MH (Nickel Metal Hydride) technology.
With no memory affect these batteries can be topped up or charged at anytime without affecting battery life.
Ni-MH batteries also tend to out-perform Ni-CD batteries in high drain applications.