In a nutshell

Neumann SG-AK passive swivel, released after the Schoeps GVC, is for KM 100 series and allows the AK capsule to be swiveled and orientated through a 90° (120° for the Schoeps GVC) maximal angle in only one direction. Like its competitor, it is a passive adaptator. The Neumann system could be reproached for fragile connectors and easily oxidizing.