It clamps to the ribs and a gooseneck mounts on it.
MC 4 - Clip Double Bass
I like it in principle as the ribs vibrate less than than the bridge, afterlengths, or tailpiece. I haven't tried this or an H-clamp but the gooseneck looks a little short on the Neumann site and from what I've read here the H-clamp is finicky.
Incidentally, here's a system I've started trialling. It's an ATM350 capsule liberated of its noisy foam and gooseneck and strapped to the treble bridge leg with a cable wrap and soft foam. Works well enough for reinforcement. Haven't tried with a drummer yet but it did well with a 9-player free improv group last week.