My "Old School" M4 and 551 have not arrived yet. So I am testing all the parts(you can see the LaRue riser and Mason pad) on my other guns. Turns out it works great on AK105. I will call it Delta AK until the m4 arrives.
I’ve found that everything I’ve purchased from these guys to be very reliable well made and good quality I’ve bought several items from them and haven’t been disappointed with any of them