The DiMarzio DP169 Virtual P90™ is a hum-cancelling P90 soapbar pickup.
The original single-coil P90 "soapbar" design had a special sound; low notes were solid and not tubby — they had an almost "piano" tone quality — while high notes were fat all the way up the neck. DiMarzio always thought this was a devastating combination, and they naturally wanted to reproduce this sound without 60-cycle hum.
In the end, they found the best approach was to use their patented Virtual Vintage® technology to create the Virtual P90™. The two coils are tuned to different frequency ranges and output voltages, so tone and balance can be tuned by adjusting pole piece heights. It's almost the same effect as adjustable high-fidelity speaker crossovers.
An obvious question is how the Virtual P90™ differs from the DiMarzio DLX-90™. The Virtual P90™ is a little more raw-sounding: high notes have a little more snap, and low notes more growl. If you have a fairly warm-sounding guitar and amp setup, the Virtual P90 would be a good choice for neck and bridge positions. If your guitar is more on the bright side, try the Virtual P90™ in the neck and the DLX-90™ in the bridge. Not available in a "dog-ear" version.