Identify This Trigger Pack

I need to know what type of rifle this trigger pack will fit. I believe its an HK rifle but not positive. Also if anyone knows if it will fit HK copies.
Thanks

Looks like an H&K trigger group to me.

That would appear to be an MP5 lower half. I'm no expert, but that is what i think it is.

I don't know the specifics regarding H&K firearms, but that trigger unit may not "drop in" H&K type rifles.

My understanding is that the CETME/G3 type rifles and their clones need to be modified with a "shelf" replacing the front trigger pack pin due to BATFE rulings.

I don't know enough about H&K firearms to really help, but you could probably find more information on a H&K specific forum.

In it's present form, that lower will fit registered receivered MP5, HK53, or G3s. It won't work on any of the semi auto HK/clones.

It's a standard, unmodified (ie full auto), HK plastic SEF gripframe.

In it's present, unmodified, state, it's fully legal to own, but must be properly modified to fit and function on a HK-9x series.