The K1 and K2 are similar in Design, how they work with the K1/K2 accessories and can be added in the smanos home app. The one and only difference is the K2 hub is able to connect Z-wave (plus) certified devices.
K2 supports Z-Wave protocols. It is a Z-Wave-certified controller using Z-Wave’s latest S2 technology. It can be included in any Z-Wave network and work with other Z-Wave certified devices from other manufacturers.