This is probably a stupid question but I sure don't know the answer. I have a GWS reciever - GWR-4N Naro Type Reciever. I have no idea what battery to get for it. The specs are

General Specs:
- Digital: No
- Range: 1000 feet
- Receiver Shift
- Voltage: 4.8 - 6.0
- .27 ounces
- 1.18 x .79 x .37 inches

Is the votage the only thing I need to worry about or do I need to be concerned with the mAh as well.

Thanks for any help.