The OptoLED controls two LEDs independently, and it also give a very stable optical output thanks to its optical feedback option.  The LEDs can also be pulsed on and off extremely rapidly, with switching times on the order of 100 nanoseconds.  LED intensity is controllable either by varying a continuous current, or by varying the lengths of high-frequency current pulses, or some combination of the two.

The OptoLED Lite now also controls 2 LEDs but is primarily intended for less demanding applications, as it lacks the optical feedback and high-frequency pulsing capabilities of its bigger brother.  However, it is still capable of operating over a wide current range, and it has switching times of just a few microseconds.  It is an ideal alternative to quartz halogen lamps for general-purpose illumination requirements, while still having a sufficiently high performance for many quantitative measurement applications.