The Additional battery compartment adds another 4x AA batteries to your strobe (total is 8xAA batteries). It is easily mounted and very secure so you can hold on to it while adjusting the strobe in water.

SPECIFICATIONS:

• Recycle time at 100% power is 1 second (8x Eneloop pro)
• Full power flash at 0,5 Hz rate: 900x (8x Eneloop pro)
• It weighs 145g (excluding batteries) and is supplied with a neoprene protector to make it neutral in the water.