The OPI1270 and OPI1280 consist of a visible Red LED and a Phototransistor sensor, which are housed in separate opaque molded plastic housings and coupled by flexible plastic cable. The OPI1290 consists of a visible Red LED and a Photologic® Totem-Pole output sensor, which are also housed in separate opaque molded plastic housings and coupled by a flexible plastic cable. The heavy-duty opaque housing shields the optical signal from dust, making this series of devices ideal for dust contaminated environments. The isolation voltage is greater than 20,000 volts for all versions of the OPI1270, OPI1280 and OPI1290. These parts are designed for applications that require high voltage isolation between input and output or signal communication over short distances (up to 1 meter). Depending on the length of the flexible plastic cable, the emitter does not have to be optically in-line with the sensor. It can be used in electrical isolation in dirty environments, industrial equipment, and medical equipment. Custom cable lengths, electrical wire and cabling and connectors are available.