This is a magazine sleeve for the Glock 22 magazine to fit a Glock 27 Compact Carry pistol. I also put an indent in the sleeve for the pinky finger to rest in. They want $12 online for a magazine sleeve so I made my own. And it only cost me $0.26 Print it out, slide it on and you're good to go.
Note: I made it to be a tight fit on my magazines using my printer. You may have to sand the inside a little bit to get it to fit from your printer.