nowt.
it’s a box
to be fair, the front panel is much thinner than the sides, top & bottom; the backplate is similar to the sides, but in mine there’s a 4in circular hole
The front plate has little “snares” across the back of the top 3-4in, this is where you get the ‘snare drum’ mimicking sound; the rest of the front plate is used to play the ‘bass drum’ and ‘tom’ patterns. all of this with your hands. Feet can be used to apply damping as required if you have the skillz.
if you imagine a rock beat such as We Will Rock You, which goes “1 and 2, 3 and 4, 1 and 2, 3 and 4” and so on, you’d play the “1 and” and the “3 and” with both hands on the lower part, and the “2” and “4” with both hands on the top edge, with a slight delay between left & right to get the flam effect that Roger Taylor gets on the snare drum. With me?