Advantage Arms Conversion Kit, 22 LR, 4 Threaded Barrel, Fits Glock 26/27 Gen1-5, Optic Ready, (2)-15 Round Magazines, Includes Range Bag AAC26-27G1-5MOD Advantage Arms Conversion Kit: Convert your 9mm/.40 S&W Glock down to 22LR so trips to the range don't break the bank. Or if you want to teach your kid the fun of shooting but don't want him/her to start on the 9mm" a conversion kit is a great learning / training tool for your collection.