Roland TD-20K Owner's Manual page 8

KD-120 (V-Kick Trigger Pad)
When Using a Twin (Double Kick) Pedal
With the KD-120, you can also play using a twin (double kick) pedal.
Set this up so that the striking points of the two beaters fall at equal distances to the left and right of the center of the head.
fig.13
* When using a twin (double kick) pedal, as with a regular pedal, use the included beater or a plastic beater as the beater for the kick pedal.
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