Small very nice unit when connected to a Raspberry Pi. A market immediately to 115200 bps when I could be sure that his connection was fine. Only downside: no plan for fixing it: If holes are drilled in the circuit board, there is no guarantee that we will not cut a track. My solution: desoldering the brackets of subd-9 connector, cut to restore the facade as nuts bolts (which are a bit too long) and move the screws in the liberated holes, expanded to 3mm diameter.