NEWTON Equipment was founded in 1978 as a producer of specialist parts for motorcycles. Initially the company was involved with the manufacture of custom aluminium fuel tanks for motorcycles. In those early days it sometimes took longer to source a filler cap than to make a tank, so we did not take much persuading to design and develop our own product. The first Aero filler cap, the Aero 400, so called because it has a 4.00" (inch) bolt circle, was right from the start. It set the standard for quality of design and finish that has paid handsome dividends. The subsequent introduction of a locking version has ensured that this model is still as popular today as it was when first introduced more twenty years ago. The success of the Aero 400, coupled with encouragement from our customers, led us to design and develop a range of Aero filler caps, which incorporated optional connecting necks, starting with the Aero 300, then the Aero 200 and finally completing the Aero range with the Aero 500. We have always remembered the struggles we sometimes had to fit other makers' offerings so we have always included with our filler caps the necessary fixing screws, nuts and washers as well as the correct fuel resistant gaskets.