The OPTEK TECHNOLOGY OPB817Z is a slotted optical switch with a NPN phototransistor output. It features a slot size of 0.20" wide x 0.86" deep, making it an ideal choice for various applications. The switch comes with 24"/26AWG wires for easy installation and connection. With its reliable performance and durable construction, the OPB817Z is an excellent optoelectronic solution for sensing and detection needs.