100 Pack - Genuine GI US Military Shelby Can Openers P-38 - Fits On Key chain. Great Backpacking Tool! The Army's greatest invention. Small and light to carry around. Faster than a normal can opener if the user has sufficient experience. Also known as a John Wayne, so named because the actor was shown in a training film using it. The can opener is a small folding blade used to open canned rations (such as K-rations or C-rations) among many other uses. List of uses by the pentagon: 1. Can opener, 2. Seam ripper, 3. Screwdriver, 4. Clean fingernails, 5. Cut fishing line, 6. Open paint cans,7. Window scraper, 8. Scrape around floor corners, 9. Digging, 10. Clean out groove on Tupperware lids, 11. Reach in and clean out small cracks, 12. Scrape around edge of boots, 13. Bottle opener, 14. Gut fish (in the field), 15. Scale fish (in the field), 16. Test for 'done-ness' when baking on a camp fire, 17. Prying items, 18. Strip wire, 19. Scrape pans in the field, 20. Lift key on flip top cans, 21. Chisel, 22. Barter, 23. Marking tool, 24. Deflating tires, 25. Clean sole of boot/shoe, 26. Pick teeth, 27. Measurement, 28. Striking flint, 29. Stirring coffee, 30. Puncturing plastic coating, 31. Knocking on doors, 32. Morse code, 33. Box cutter, 34. Opening letters, 35. Write emergency messages, 36. Scratch an itch, 37. Save as a souvenir, 38. Rip off rank for on-the-spot promotions, 39. Bee sting removal tool (scrape off with blade).