There is no mag for this but i like it 100% you can put it at the end of any gun that is comaptible, to use on the ZLG remove the bullet lock, you won't need it since this baby shoots 60 feet with 5 or so bands, highly recommended!!! Now to build there is some pictures and a video for the people who are not sure about it. If it stuffs up, then you haven't made it properly or you didn't read this!!!
Disclaimer: I am not responsible for any damage occured by this object and cannot be sued or be fined or compensated. PLease note that building this may require some skill.