In Treble position you can use 3 of the controls.

• Bridge Volume-Coil Cut- When this control engages it changes the Bridge pickup from a hum canceling humbucker to a single coil
• Bridge Tone-Phasing- When you engage the Bridge tone you flip the bridge humbuckers wiring. the Hot Output becomes the Ground, the Ground becomes the Hot. The sound now passes through the pickup in reverse.You wont hear much of a difference in the treble position but with some pickups it can change the sharpness at the higher range.  
• Neck Tone-Kill Switch- When you engage what would be the Series switch in the Middle and rhythm positions. In the Treble position you get a cool Kill Switch/Output Limiter
  • This only works in Treble becasue the series switch is removing the bridge pickup from the volume and installing it to the back of the neck pickup

The Middle Position is the most versatile when using the controls.

Volume Controls-Coil Cut- When these controls engage it changes the pickups from a hum canceling Humbucker to a Single coil and even a giant humbucker.

Bridge Tone-Phasing- When you engage the Bridge tone you flip the Bridge humbuckers wiring. the hot output becomes the ground, the ground becomes the hot. The bridges sound passes through in reverse of the Neck pickups.

Neck Tone-Series- When you engage the series you hear the 2 humbuckers turn into one giant humbucker creating a more fuller sound

Rhythm position is basically the same as the Middle position. Although when the Series switch is down, you will only have the Neck pickup