This is the F-Spaced version of the DP151 pickup for Floyd Rose and other wide-spaced tremelo bridges. The string spacing is just over 2 inches from E to E on center. All other dimensions are the same as the standard spaced pickup.
The DiMarzio PAF Pro® was created when chops-intensive playing was first starting to happen, and high-gain amps and rack systems were becoming popular. A pickup was needed that combined a lot of presence and "cut" with an open-sounding PAF vibe. The transparency of its sound lets the PAF Pro slice through heavy processing, where darker-sounding pickups get lost in the mud of the effects chain.
Low notes have both snap and chunk, and there is a spike in the mid-range that gives the pickup a subtle "aw" vowel sound, like a wah-wah pedal stopped in the middle. Treble response is tweaked to produce highs that stand out without getting brittle.
This is an exceptional bridge pickup when high output isn't required. As a bridge pickup, it's really effective with single-coils, because it won't drown them out with too much power, and it's bright enough to blend in tone-wise.