Model ALPHAModel ALPHA Features:Phosphated Kit25 Round Magazine Piston System Compatible Available Upgrades but not included:Forward AssistAnti-Jam Charging HandleBHOA AdapterEvolution MagazineStainless Steel Cleaning Jag/Guide RodMagazine Loader All CMMG .22 LR magazines have a bolt hold open follower. When using the bolt hold open follower, magazine will only hold 25 rounds. For best performance use a round style hammer, notched hammers can cause function issues. 36 grain bullets have proven to be the best choice for function. The PRI Gas Buster charging handle will not work with our .22 Conversion kit.Set up is less than 30 seconds. Ammo is 1/10 of the price of 5.56 ammo, so a significant savings to you.