Have a look at our quality optocouplers (also know as opto-isolators) including 4N25, -26, -28, -30, and -32 varieties which transfer electrical signals using lights waves in order to provide electrically isolated coupling between input and output. Circuit Specialists' general purpose optocouplers have gallium arsenide infrared-emitting diodes which drive silicon phototransistors in six-pin dual inline packages. Reduced prices when you buy in bulk.