Features:
1) The ability to charge 3 sizes of rechargeable batteries-AA, AAA or 9V
2) Can charge either 2 or 4 AA or AAA size batteries or 1 or 2.9V in
Nickel Hydride technology
3) Automatic cut-off after 15 hour
4) Extended charge times significantly prolong battery life
5) This pack comes complete with two environment friendly (0% Cadmium)
Nickel Hydride AA size batteries, which offer over 80% more capacity
than standard 600mAh

Nickel Hydride batteries:
1) Can be recharged up to 1,000 times with no "memory effect"
2) Best performance especially for high drain applications