There's a lot of boost on tap here: up to 34dB. That kind of boost will send your amp into beast mode; it's some serious extra gain. The tone is still nice and transparent, although the high cut/boost function can add some sauce to the tone if required. 

Model: Seymour Duncan Killing Floor
Made: Santa Barbara, USA, recent model
Type: booster
Power: standard 9v supply or battery
Switching: true bypass
Draw: 5mA approx
Dimesions, excluding switches/knobs/jacks: 125x66x37mm
Equivalent new street price (approx): $269aud
Mods: none
Accessories: original box, manual and docs
Condition notes: used, no major marks, excellent condition

Controls
Gain: gain added to the signal
Toggle: neutral boost in the middle, adds high end sparkle when up, darkens tone slightly when down