This is an old pic, in the meantime I've added some more buttons...
There's a total of 6 sliders, three of them for trim.
They work, but level flight... still can't get that under control...
White thing top left is throttle (up-down), the red thingy right behind is for flaps (goes left-right), black one to the right of that is for proppitch. (up-down)
The red one to its right is the elevator trim.
Below that, the red one (left-right) is aileron trim, to the left (left-right) is rudder trim.
(Directions are as-you-view the picture, IRL the throttle and pitch levers rather move fore and aft.)
The truly amazing thing of this box is that it actually works, and I only have to open it up maybe once a year to fix a loose wire...