3 channel tom expander with 3 trigger inputs, midi in (no midi out!). Developed as an extension for the SDS 9 which only offered analog sound generation for the toms.
For sure this is not the most essential product Simmons had produced as it has digital sound generation and cannot produce this famous analog sound e.g. like the SDS 5. Nevertheless it might be a nice extension to a conventional drum kit because it is normally not so expensive when beeing offered.
Special: digital delay.