The MK is the "Micro-Kahr" which is a K9 with a shorter slide and frame butt.
It will fit the K9 holsters, but the holster will be too long for it.
You can use K9 magazines in the Micro, but if you slam them in, they will go TOO far and damage gun and magazine.
I "think" Kahr or someone makes an adapter that slips over the K9 magazines and act as a stop when using the magazine in the shorter MK9.