need some help ID'ing a mag. friend of mine has a mag w/ absolutely no markings. thought they were KCI. however there are no witness holes either. he says they shoot fine. i did a few searches to no avail. also googled it. nothing came close. obviously a knock-off, but whose? other info: -no markings (from above) -no witness holes (from above) -fits a g19 -15 rds. of 9mm -all polymer -top is 'U' cut ideas?