The OPB100 series, from Optek Technology, consist of optical emitters and sensors. The IR LED and the phototransistor come in separate plastic housings and can be purchased individually or together (OPB100Z). Their snap-in package design enables easy installation without any need for additional mounting hardware.
The emitter and sensor do not require precise alignment due to no aperture. They are designed for general switching and low speed data communication applications, for example; non-contact reflective objects, non-contact interruptive sensing, assembly line automation, machine automation and machine safety.

OPB100-EZ: IR LED
OPB100-SZ: Phototransistor
OPB100Z: Contains both OPB100-EZ and OPB100-SZ

Infrared (IR) Transceivers, Optek