This is a premium quality re-arming CO2 kit/cylinder/cartridge for manual version of inflatable jackets, life vests, waist belt packs, or personal flotation device (PFD). It fits lifejackets that take 1/2-inch thread CO2 cartridges. Manually inflates when the wearer pulls the inflation handle of the life jacket. For replacement CO2 cartridge, use our premium rearming kit. Features and Benefits: * This CO2 rearming kit inflates your manual version of inflatable lifejackets. * Premium quality, heavy-duty, easy to install and remove. * Fits various size inflatable lifejackets with 1/2-inch thread cylinder. Great customer service. CO2 size and flotation/buoyancy reference: 33g = 150N (for adult lifejacket) Note: please select the CO2 cylinder size that matches your lifejacket buoyancy rating. (Important: To ensure 100% compatibility, please make sure your lifejacket takes 1/2-inch thread CO2 cartridges. And it's always recommended to buy the CO2 rearming kit from the same seller that you bought your lifejacket/life vest from.) What's in the box: CO2 cylinder, green indicator clip, and instructions. Reminder: This cylinder is one-time use only. Since it is hard to be transported, we suggest you to buy 1 or more extra CO2 recharge set while purchasing the inflatable life jacket at the same time.