SH-21 - 

SH Series Ultra Slim/Compact Photoelectric Sensors
The SH series photoelectric sensor offer a great alternative to where space is at a premium. The SH-2 range has an ultra slim body with thickness measuring only 3 mm. The SH-3 range has an extremely compact body yet still offers a sensing distance of up to 2 meters. They have limit sensitivity settings where the user can adjust the sensitivity for detecting minute differences with the push of a button without the presence of an object. The user can also set the sensitivity threshold level from center towards either on or off level. The units offer sensitivity margin indication. The number of blinks of the stability indicator indicates the degree of the sensitivity margin. All units have built in interference prevention allowing two sensor heads to be mounted close together.