There are two Panasonic RT-610 u-shaped photoelectric sensor models having a sensing range of 10 mm 0.394 in, and 50 mm 1.969 in. The models with sensing ranges of 10 mm 0.394 in are also available in red LED type and green LED type for mark sensing. Beam axis alignment is not required as the emitter and the receiver are integrated in a single body. The robust die-cast enclosure maintains high reliability.