I've only carried a little Gerber LST , 1.2 oz and a P-38 (G.I. can opener) , 0.2 oz, for years. Given how many canned goods are now pull tab, that may well leave my cook kit as well. Some UL fanatics snarl at cans as being too heavy, but an empty tuna can really doesn't weigh much and you get all the good olive oil with your albacore that way too - the foil packs are much dryer. I also carry a little swiss card tool , 0.9 oz, that has scissors, a file, mini knife, tweezers, pin, pen, and LED light in my first aid kit. It's admittedly rarely if ever used and could be left behind. It was a freebie - I wouldn't buy one at retail prices.