The OPTEK TECHNOLOGY OPB804 is a slotted optical switch with a phototransistor output. This compact device features a slot size of 0.155" wide and 0.33" deep, making it ideal for various applications. The OPB804 has a PCB through-hole design, allowing for easy installation and integration into electronic circuits. This optical switch provides reliable and accurate detection of objects within the slot, making it suitable for applications such as position sensing, object counting, and speed detection. With its high-quality construction and precise optical performance, the OPB804 is an excellent choice for optical sensing needs.