As a primary, this super bright dive light cant be beaten. It puts out a narrow penetrating beam for the night, wrecks and caves. Pushing the large rear switch button selects 3 levels of brightness as well as emergency flash mode. As a photographer, you can slip in the diffusion filter for smooth wide-angle illumination. Two extra-large lithium batteries are removed for charging and can be replaced with an extra set for all-day diving without recharge. The handgrip and Aqualite photo arms are all compatible