VentMask Vent Register Filters (2) Two 7.75 Slim design make VentMask visually and physically unobtrusive. Once installed VentMask virtually become invisible because they look like the vent register itself while providing superior filtration removing the particulate missed by main filters or build up inside the ducting before they can be reintroduced into your room. Designed to fit into any carry-on bag or suitcase, VentMask filters take less space than a magazine and will provide you with cleaner air in any hotel. Protect yourself with VentMask from air borne particulate like mold spores, pet or rodent dander and feces matter that can be inside air ducting. No tools, vent removal, cutting, or trimming to size needed to install or replace. Peel-N-Stick to apply make VentMask a solution for cleaner air in your HOME, or for people on the go...HOTEL!