DiMarzio. Crunch Lab DP228.

The name says it all—"crunch" is what it’s all about, delivering a powerful, tight sound that’s neither muddy nor thin.
This pickup laid the foundation for the late ’80s progressive metal tone favored by players like Petrucci. The difference is that it has now been refined and updated by the master of "Theater." "Black Clouds & Silver Lining" is a perfect example.

Technical note: The Crunch Lab is famous for what it DOESN’T do. This pickup is NOT a shredder. It doesn’t have ultra-heavy bass. Its look resembles the D-Sonic, but that’s where the similarity ends. It’s powerful, but with much more open bass and mids (less compression). The highs are much deeper. Designed to deliver clear chord definition through gain stages.
So versatile and distinctive that Mr. Petrucci has installed it in nearly all his instruments...

Recommended position: Bridge
Specifications: Ceramic magnet
Output: 410
DC Resistance: 11.03 K, 11.07 K in Crunch Lab 7
Tone: Highs: 4.5 Mids: 5.5 Lows: 6