If you're here, you know what this is! Particle Accelerator Mini-Tube, which has a lot more low end than the 12AX7 version and has an overall deeper, smoother tone. This one is in the custom Apple Sparkle Green color. I love these pedals, but I just don't need 4 of them $150 shipped and Paypalled, lower 48 only. Might consider a Slampegg in trade, either version. Will also trade towards the new Empress Bass Compressor (not an MKII). Long shot, but worth a try!