What is “Combo FX” on the Hardware Diagram for TRAKTOR PRO 2?

Combo FX allows additional effects to be applied by pressing multiple pads in a specific order when the Instant FX mode 1 is set (when the pad mode is set to the roll mode).

Combo FX 1:

The [Transpose Stretch] effect is added when pad 5 -> pad 6 -> pad 7 -> pad 8 are pressed and held, in that order.

Combo FX 2:

The FX 3 [Filter:92 LFO] and [Delay T3] parameters gradually increase when pad 6 -> pad 7 -> pad 2 -> pad 3 are pressed and held, in that order.