The pE-100 Series is a mercury-free family of compact and simple to use LED illumination systems which can be configured to deliver light directly to a microscope, or via a liquid light guide or multimode fiber. Systems can be specified at any one of 20 different LED wavelengths. Operation is by a remote manual control pod with instant on/off and intensity control from 0-100%. Remote control is available via a TTL trigger. The system has been developed for applications requiring a single LED excitation wavelength. It is perfect for clinical applications such as routine screening (e.g. using Auramine for Tuberculosis), for research applications requiring precise intensity control and fast-switching, or for electrophysiology applications where light has to be delivered to a specific location. The user can select from 20 different LED wavelengths, ranging from the near-UV at 365nm to the near-IR at 770nm. The system comprises a pE-100 LED Light Source, control pod, and power supply. There are three standard pE-100 configuration options: Direct-fit (pE-100) for connecting to a microscope by selecting from a range of microscope adaptors which covers all current and most older models. A simple once only adjustment will allow optimisation to the optical path of the microscope. Liquid Light Guide (pE-100light guide) with a fixed 3mm diameter, liquid light guide Fiber(pE-100fiber) with an SMA connection for accepting multimode fibers. The pE-100fiber has been designed with efficient coupling into a wide range of multimode fibers. The pE-100fiber also includes excitation filter holders. Combining pE-100s: Direct fit configurationpE-100 units can be combined using the pE-Combiner for applications requiring a second LED wavelength with independent control and triggering. Liquid light guide or multimode fiber using a fixed two wavelength configuration can be specified. Two pE-100 Light Sources are combined, providing independent control and triggering.