This is the world's smallest remote-control submarine, only 7.5cm long! It features a ballast mechanism just like a full-size submarine, capable of vertical movement, advancing, retreating, turning left or right while diving or surfacing, and so much more! Operable distance is about 1 meter, operates for about 30 minutes on a charge. Requires about 35 minutes charging time. Rechargeable lithium ion polymer battery included for the submarine itself. The charger requires 4 AA-size batteries, not included.