The RK-16 Re-Arm Kit, with a 16-gram CO2 cylinder is compatible with all Bluestorm® Cirro16 manual belt packs. The Bluestorm® RK-16 contains all the part you need to easily re-arm your life jacket and get back on the water quickly. All Bluestorm® inflatable life jackets feature an internal pocket to store a spare cylinder, just in case you need it. So remember to pick up an extra kit for your life jacket.