Fender Jazz Bass ( J Bass ) replacement pickup set with a 'long' for the bridge and a 'short' for the neck. They feature a dual in-line coil design. The "original series" bass pickups with passive designs. The lengths of the neck and bridge pickups in the original J-basses are not equal. The neck pickup is 3-5/8″ long which is slightly shorter than the bridge pickup which is 3-3/4″ long. Some modern designs, however, use two 'long' bridge-length pickups. In this configuration, it is important to use the "LN" (long neck) pickup that is specifically designed to work in this position (do not use a bridge pickup in the neck position). Please check the physical size of the pickups you want to replace to make sure the replacements fit properly.