aftermarket

Parts made by an outside firm to replace OEM (Original Equipment Manufacturers) parts. Commonly used in automotive purposes, but the aftermarket exists in virtually every industry. In other words, these are NOT "Genuine <fill in name of manufacturer> parts." The quality of aftermarket parts can vary widely, some engineered to be better than the originals, some poorly fitting and otherwise inferior crap. Caveat Emptor when buying aftermarket parts! But sometimes when the original parts are discontinued or the manufacturer has gone out of business, the aftermarket may be your only choice.