This personal air filter by Eco Four Twenty is so easy to use, simply exhale smoke through this device to reduce harmful second-hand smoke and odour that can affect your roommates, family and neighbours. This device's casing is made of high-quality aircraft-grade aluminum and 2 stage medical-grade filter with activated coconut shell-carbon filter + HEPA filter. It lasts up to 500 exhales, instead of buying a whole new filter you'll only have to replace it with another Eco Four Twenty filter cartridge. Backed by Eco Four Twenty's Lifetime Warranty and their 100% satisfaction guarantee, you will not be disappointed.