The GE automatic safety night light will turn on when it gets dark and turn itself off at morning time. This great night light was designed with safety in mind- especially for children. It mounts directly over and covers an entire outlet wall plate so it acts as a cover plate preventing access. The bulb is a cool burning 4 watts so it uses very little energy and it is fully enclosed so it can not be touched (and cause burns). The bulb comes with a 3 year guarantee. Note: this item is for use with duplex receptacles with center-screw wall plate mounting. Use only with plastic wall plates. It measures 4 and one quarter inches x 2 and one half inches x 2 inches.