What you see here is Duncan's "spin-a-split" wiring dealy. The downside is you lose your tone knob. But here's what it does instead. When the tone knob is at 0, your pickup is tapped...single coil operation. When the tone knob is at 10, your pickup is in full humbucking mode. And when the tone knob is somehwere in between...your pickup is...somewhere in between (P-90 anyone?). It's like having a 'bucker, p-90, and a single coil all in teh same position on your guitar.