Standard Base

Light bulbs come in a variety of shapes and sizes and can be categorized by the shape of their bases (the part of the bulb that screws into a light socket). Medium screw (E26) bases are considered standard, and the size of a standard bulb's base is 26mm in diameter. These are common in many lighting applications and can be used in any appliance with a 26mm (approximately 1.02in) socket.