The right side of the box is the Kick Box™ interface which allows you to connect your ion, rb1, rb2, or wii drums to your own electronic kick trigger. Seamlessly integrates with Rock Band.

Use the Alt kick pedal input override to connect a rockband pedal.  Useful for getting into song category view or guest players who want to use the rb pedal.

HH Kick Box™

The left side of the box is the HH interface which seamlessly integrates ion or after market cymbals to your ion drums with adjustable sensitivity.
Use your ion pedal, Roland FD hh pedal, or old rockband pedal as a HiHat pedal.  Pedal down, yellow plays (closed Hi-Hat) , pedal up blue plays (open hh or ride).   Plenty of gain to adjust the cymbal sensitivity up or down to your playing style.

You can also use the HH without a pedal for other reasons.

Boost your HH and Ride cymbal sensitivity.

Merge 2 Green Cymbals to have right and left Crash with independant sensitivity control.