The Switch-Itt and Wilcom ROM Switcher are actually the same design.
The Switch-Itt is allows you to switch between different versions of Kickstart without having to keep removing chips and is compatible with the A500, A500+, A600, A1500, A2000 and A2500. It holds two kickstart chips and allows switching between the two by holding down CTRL-LAMIGA-RAMIGA for about 3-4 seconds. If switching to the alternate ROM is made a high pitched tone is produced and if reverting the original kickstart, a low pitch tone is produced. The SWITCH-Itt draws power from a clip that attaches to pin 18 of the 68000 CPU.
Jumpers
Apparently the jumper layout may differ slightly from the instructions supplied with the unit.
ROM 1/2 - Sets the default kickstart ROM. (ROM 1 is on the left, near the ribbon cable)
J2 - Controls whether tones should be generated when switching ROMS
J6 - If closed, disables the buzzer.
J7 - Unknown (Possibly for Pin 31, 1 remapping)
J8 - Unknown (Possibly for Pin 31, 1 remapping)
J9 and J3 - Control ROM versions, both most be open of Kickstart 3.1