Enviro-Safe was the first company in the U.S. to package Green Gas for law enforcement and the military in a DOT approved can. Other brands use mercaptan in their propane canisters. Mercaptan will damage and corrode your gun's seals and does not offer any lubrication benefits. Enviro-Safe Green Gas adds silicone oil to help keep your airsoft gun lubricated while the pharmaceutical-grade gas helps to prevent jamming and protect your gun's seals. Green Gas is: Non-ozone depleting Non- Global Warming Made with pharmaceutical-grade gas Usable for 1,500+ shots Made in the USA! ONLY for use with compressed gas airsoft