Speaker decouplers aim to isolate speakers from the surface on which they sit. This newer, more affordbale DMSD 50 Pro design has been optimised for speakers weighing up to 12kg (ie. most nearfield monitors).
All the stands in this range are intended to decouple a speaker from the desk or studio furniture on which it sits. Where this model differs is in its size — 17 inches wide by nine inches deep, making it suitable for speakers with a larger footprint.