As to the question of rules regarding when and where peaceful protests may be held, that's highly dependent on the specific location of the protest.
The venturi mask, also known as an air-entrainment mask (and sometimes by the brand name VentimaskÂ®), is a medical device to deliver a known oxygen concentration to patients on controlled oxygen therapy.
Product Description. We've found a stash of these authentic military surplus gas masks, and we're passing the savings on to you with our unbeatable pricing! This like-new Czech M10M gas mask helps to protect the face, eyes and respiratory system against chemical and biological warfare agents in the form of gases, vapors, aerosols and more. Includes bag, spare goggles, straw and filter.