I recently purchased a new magazine for my Umarex Bullshark. The stock mags are ok and the Carm one a step better but this new one is better yet. BIG AIR PRECISION is the name of the company where I purchased them. They have a special still going buy 3 get one free. I bought three for my Bullshark and one for my Origin/Avenger. All the mags hold twelve pellets instead of 9 or 10. Easy to load and the Origin/Avenger one snaps into place. I sure think these are the best mags out there for my two guns. He makes them for other models also.