David Gilmour’s black Stratocaster has the stock pickups in the neck and middle positions. The bridge pickup, however, is a custom Seymour Duncan pickup, custom-made for David.
The bridge pickup is an overwound version of the SSL-1, called the SSL-5 (previously known as the SSL1-C). When compared to the stock bridge pickup, the SSL-5 has more mids and a beefier tone.