An allen wrench for the pickup poles screws is included (it comes stuck to the back of the pickup). Don't forget it and install the pickup with your wrench still stuck to the back!
From the manufacturer:
One thing has stayed consistent throughout John Petrucci’s long and successful career: the DiMarzio® pickups in his guitars. John has been pushing the envelope of progressive metal since the late eighties, and the new DiMarzio® Crunch Lab™ Bridge Model ensued from our most recent collaboration with John. He used it throughout Dream Theater’s tenth studio album, “Black Clouds & Silver Linings”. John swears this is the best live and studio sound he has ever had, and the name says it all — “crunch” is what it’s all about with a big, tight sound that’s neither muddy nor thin.
The Crunch Lab™ is noteworthy (bad pun alert) for what it doesn’t do: it’s not a screamer, and it’s not about thundering lows. Its physical appearance is identical to the D Sonic™, but the internal design is a lot different. It’s louder, and the highs have more depth. The lows and mids are more open, and this is crucial for playing chords with body and presence through a gained-out amp. The voicing of the pickup is also different enough to the point that John prefers the Crunch Lab™ to be installed in almost all of his guitars (including the JP Bari) with the solid bar toward the neck, regardless of the guitar’s tuning.
Best videos/sound clips:
Here's a video by Tom Montalk showing a comparison of the DP228 Crunch Lab vs. the DP257 Illuminator (both John Petrucci bridge pickups from different eras - the Crunch Lab is from 2010 and the Illuminator 2013). The same phrases are played on the same guitar with the different pickups, back-to-back. He starts clean and gets dirtier. The order is always Crunch Lab then Illuminator. Make sure to stick around to the end of the video - a mix is added in around 3:40 which adds a new element. Each pickup brings its own benefits here - for me they are both great and this one is tough to call!
Given the great playing and recording of his prior video I'm going to double down here with another Tom Montalk comparison! This one compares the Crunch Lab to the Seymour Duncan Custom (SH-5). The backing tracks start at about 2:14 on this one.
Lucas Fowler here is playing the Crunch Lab bridge paired with the PAF Pro neck. Great video with some killer playing. He calls out why he replaced the stock pickups, which was that he found the bridge to be too hot and the neck to be too muddy. A lot of folks I'd imagine are pairing the DiMarzio Liquifire neck with the Crunch Lab bridge, but he opted for the PAF Pro to fight the muddiness of the guitar and keep it bright. Lucas is playing a PRS Tremonti through a Mesa Mark IV combo. The audio is good as promised! (He mutes his mic when playing). I also appreciated the coil-tapping demo, which sounded good with both pickups and provides a nice extra flavor.
Here Guitar World's Paul Riario reviews the Crunch Lab bridge and LiquiFire neck pickups in a Reverend Les Paul-style guitar. The tones on display here are very much of the singing/crunchy Dream Theater variety, but some jazzy riffs come in at 2:27 with both pickups on.
Steve Kay here is playing some really expressive freestyle riffs through his Charvel San Dimas with the Crunch Lab bridge and LiquiFire neck. He switches back and forth between the pickups as the video goes on though you can see the selector in the video and he also has the pickup name appear on the screen so you know what you're listening to. Steve is playing through Amplitude with a Marshall Plexi modeled and a modeled tubescreamer driving it. Audio quality is only average but the playing makes this one a must-watch.
Dhalif here is playing some slow leads with delay on his Musicman Silhouette with Crunch Lab bridge and LiquiFire neck. Reminds me vaguely at times of Eric Johnson's Cliffs of Dover (note-wise not tone-wise). Played directly into a Line6 Pod X3. Very pretty.
JP-style riffing by wizarwylie here. Crunch Lab and LiquiFire combo installed in a '92 Jackson Kelly Professional guitar. Direct to computer with sims using Amplitude Metal.
When I read that John Petrucci strongly prefers the bar of the bridge pickup to be closest to the neck I wondered "How much of a difference would that really make?". Well - David Wallimann here took it on himself to find out. Now, it is worth noting that he is playing a Parker Fly, which is an extremely thin and lightweight guitar, but the relative comparison between the two positions on the guitar should be a good comparison, even if your guitar is nothing like his. Commenters on this video spanned the whole spectrum from "backwards obviously better" to "a draw" to "bar to neck obviously better". Actual playing starts on this video at 1:38.
Lastly, this is a bit off topic but I figure if you made it to the bottom of this page you are likely a John Petrucci fan. In case you also happen to use the (powerful but touchy) Mesa Mark V amp he uses, here is the first of the three video series on how he sets his Mark V, which I figured might be of interest and shows how he thinks about his amp setup/tones.