As the number of wounded and killed has climbed in Egypt in recent days, a number of journalists and bloggers have reported that several of the tear gas canisters being fired at protesters in Tahrir Square carry blue ‘Made in USA’ stamps, and indications that they were made by a company based in Jamestown, Pennsylvania, called Combined Tactical Systems. Comparing a recently posted picture of one such shell with the illustrations on CTS’s website suggests it may well be a 40 mm projectile with the catalogue number 4230.