The OPB991T51Z is a Photologic® Slotted Optical Switch manufactured by OPTEK Technology. This optical switch features a buffered open collector output and comes with 24"/26AWG wires for easy installation and connectivity. With its slotted design, this device can reliably detect objects passing through the slot, making it suitable for various applications such as position sensing, object detection, and speed measurement. The buffered open collector output ensures compatibility with a wide range of digital systems.