E_Z Loader is made specifically for high capacity magazines for the Ruger 10/22 and is small enough to carry in your pocket. Now you can load those magazines with ease! Once you get the rhythm going you'll be amazed how quickly you can load the magazines! The E-Z Loader works with all high capacity magazines including those from Butler Creek, Ram Line, Pro Mag and Eagle. The E-Z Loader is made of 66% nylon and 40 % mineral filled which is a very hard polymer. It is durable and resists oil, grease and acetone.