With 2 eggs you can enjoy sensations in 2 erogenous zones. The eggs (but not the controller) are water resistant so it is easy to clean. Made from non porous ABS plastic these eggs will not harbor bacteria as long as you keep them clean. The multi-speed adjustable vibrations are conveniently controlled by a twist of the dial. Vibrating bullet requires 2 AA batteries, not included. Measures 2.15 inches insertable, 1 inch wide.