American Deluxe P-bass, w/ Billy's reflection (2010)
Often known as the Fender P-Bass, this bass was first prototyped in 1950, and the first electric bass to earn widespread attention and use, and is one of the best-selling basses of all time [wiki]. It features a 34" 20-fret neck and a split humbucking pickup. The "Precision" name comes from the frets, which allowed for a precise pitch, as opposed to an acoustic upright bass, which at 42" was too large and imprecise for most guitarists attempting to play the bass.
'58 P-bass mentioned by @Billy in a tweet on 2011/06/18 about the main basses used on Oceania. A picture of Nicole crashed out on the floor, still holding her bass, was posted on the band's facebook on 2011/06/14, during the Oceania recording session. Nicole also mentioned the '58 and a '76 P-bass in a blog post on 2011/07/11.
Nicole also has an American Deluxe model P-bass in 3-color sunburst, which has an 8-pole N3 Jazz Bass bridge pickup in addition to the standard split Precision pickup.