This is for a set of ten submersible lights all with batteries included. Just twist the light it is an easy on/off switch with replaceable batteries. The battery included gives the lights 12-16 hours of operation. These are not returnable. The batteries for these are CR2032-and 2 are used in each light. The size of these lights are 1 inch in height and 1 1/4 inches in width. These lEDs can be used for weddings in arrangements.