Don Barrow Lights or 'Potis' have been at the forefront of low light and nocturnal motorsport navigation aids since their origin in the early 1970's and have changed visually very little since their introduction, still being moulded using the original dies.The Potis compact and robust body lends itself to a competition environment, whilst a crystal glass magnifier and LED illumination supply up to 50% magnification, highest levels of clarity for easier viewing even on the roughest whites and total light spread so the upcoming route can be seen.This particular version features a rheostat which enables the user to vary the amount of light on the map, depending on the amount required. This type of feature is especially useful if full power is too bright, this version also includes a baseplate for easier plotting on the move (or plot and bash events) and includes separate hook for best storage.Bulbs are 37mm Type Festoon.