A flat tire can instantly take the air out of any ride. The GP-2 includes everything needed to repair a punctured inner tube without messy glue or adhesive. Park Tool's self-adhesive patches were engineered in collaboration with 3M, and stretch, flex, twist, and turn right along with the tube, so you can continue on to your destination with confidence. Lightly roughen the tube with the included sandpaper, clean, apply patch directly to the puncture, and you're ready to reinstall, reinflate and ride.