Check the listing for details. Life Jacket Bobbin Replacement for CO2 Inflator. Condition: New with tags. Listed at 8.39 USD. Replacement Water Dissolving Bobbin for Inflatable Life Jacket / PFD (Personal Floatation Device) Replacement Yellow Bobbin is a replacement part for automatic inflators on life jackets and other personal flotation devices. Features: Replacement part for automatic inflators on life jackets or inflatable devices that use CO2 cartridges. Bobbin dissolves when immersed in water and causes the CO2 cylinder to inflate the Personal Flotation Device. This Life Jacket/PFD (Personal Flotation Device) Replacement Yellow Bobbin is a replacement part for automatic inflators. Universal Fit. Features: Replacement part for automatic inflators on life jackets or inflatable devices that use CO2 cartridges Bobbin dissolves when immersed in water and causes the CO2 cylinder to inflate the Personal Flotation Device. For recreational use, bobbins should be replaced every three years to avoid inadvertent inflation. Replace Annually for commercial use. Inspect and Replace if Life Jacket has gotten wet. Long shelf life when kept in sealed packagingUniversal FitHow to Replace Bobbin see this YouTube Video https://www.youtube.com/watch?v=iUddBuQVTYg