The mophie Juice Pack is a lightweight, long-lasting USB power source that will run your Arrow transmitter (requires 1A) and/or receiver (requires 2.1A). The 4000mAh size will run either end of your Arrow system for 4-5hrs on a single charge. For an even longer battery life choose the 6000mAh Powerstation Duo model (black or white). If you only need to power your transmitter and weight is critical, the 1A 2500mAh Powerstation Mini option is your best bet (Note: The Mini will only power transmitter). Battery is guaranteed by mophie to be rechargeable for 500 cycles.

2500mAh Dimensions (USA): 3.64in x 1.92in x 0.53in
2500mAh Dimensions (metric): 9.3cm x4.9cm x1.3cm
2500mAh Weight: 2.88oz/82g

4000mAh Dimensions (USA): 4.1in x 2.3in x 0.6in
4000mAh Dimensions (metric): 10.5cm x5.8cm x1.4cm
4000mAh Weight: 3.7oz/105g

6000mAh Dimensions (USA): 4.3in x 2.3in x 0.78in
6000mAh Dimensions (metric): 10.9cm x5.8cm x2.0cm
6000mAh Weight: 7oz/198g

In the box:
1 mophie 2500mAh, 4000mAh, or 6000mAh Juice Pack
1 Micro-USB to USB charging cable
1 Instruction Manual