I purchased 20 uppers and 20 BCGs from them just for gits and shiggles because they were less than $70 shipped per set. When the order arrived, they forgot the BCGs. I called and spoke with the owner who remembered packing the box and also remembered that he had forgotten the BCGs. He sent them out the same day via 2-day UPS. Not the best quality finish on the upper, lots of machine marks on the carrier, gas key staking was sub par, but the bolts looked okay and were MPI stamped. Not sure about function because they're all still in the box.