Planet Bike 25g threaded CO2 replacement cartridges - 2 pack Our Co2 cartridges work in Planet Bike inflators as well as most competitors' inflators Our Co2 cartridges are tested to the highest standards for durability, safety and reliability. They contain Pure Co2 with no oils or contaminants 100% recyclable steel cartridges Compatible with air smith Co2, air kiss, red zeppelin and red zeppelin 3