5.2 oz, shielded on both sides, fully UN38.3 certified (air transport).
These little beasts measure 1.75" x 1.25" x 0.7" and can pump 40 liters of water before needing recharge! Completely waterproof, designed to hang from the bladder hook up top, and has internal shields to protect against punctures!
Internal charge controllers prevent over charge and over discharge.