+1... Same for the K. I use the SF K on my K and RS guns whenever I can. They are excellent.not really sure about the k version, but I know I really like the fullsize version on my 9mm mp5 clone, .40 mp5 clone, and my vector 51 SBR.
solid lockup, no marks on either of my hosts. after its adjusted, it can be installed just like the factory forend, or you can really crank it down for zero movement.
The SureFire railed hand guard is a high quality unit for sure. There aren't a lot of options out there for the SP89/MP5k like there are for the full size MP5. My experience is there's several inexpensive serviceable railed hand guards for the MP5, but for the SP89/MP5k there's either the SureFire unit or a couple others that are complete junk.What's the verdict on Surefire's railed forearm for the MP5K? It's about $200 or so and looks well made, but is it stable? Does it scratch up the paint when installed?