The PT26-21C/TR8 is a phototransistor manufactured by Everlight. It is a general-purpose IR phototransistor, which can be used for detecting water levels, switches, motion sensors, alarms, and other electronic sensing applications. The PT26-21C/TR8 has a low current transfer ratio of 0.1 mA/mW, a photo current of 0.2 mA/mW, and a gain-bandwidth product of 10MHz. The transistor has a package size of 6.5x3.3mm, and it can operate in temperatures ranging from -40? to +100?. It has a built-in lens which provides good uniformity of light spot and high sensitivity, and it requires only milliwatts of power. The PT26-21C/TR8 is an ideal choice for cost-efficient and reliable phototransistor circuits.