I have a ICS MP5 and I love this thing! I bought a vertical forgrip to go on it as well and everything works perfectly.
Like C. PFLUGER said it doesnt fit up perfectly, the metal is a little too thick around the hop up adjustment lever. However, all you have to do is take a steel file and file away the metal a little bit, it takes 2mins and then it fits perfectly!! I highly suggest this for your mp5!
Exceltent piece of equipment for the mp5. Downside is that it didnt quite fit my CA mp5a4, so I had to do a little gunsmithing to get it to work. After field testing it I say it is a neccesary item for any MP5 enthusiast. It is a real head turner at games, and makes your gun stand out from all the stock mp5s.