This came in a job lot & we are not experts in this sphere but we think this is what it is. If so here are some more details: 5.56 caliber? Apparently ‘this effectively cleans the gas regulator, gas cylinder, and piston on an M249 Squad Automatic Weapon.’
Before buying please satisfy yourself this is what you think it is. Please do call the shop if you have any other questions and we’d be very happy to help as much as we can.