Check Inflatable Life Jackets

[dubob]

The problem is that you can't buy just the bobbins or just the green safety plugs, if I read correctly. You CAN buy just the CO2 cylinder, but if the bobbin or plug goes bad, you now have two cylinders but no bobbin/plug. If you buy a recharge kit, the same thing - one excess cylinder you can't use or try. The system is predicated on you not replacing the cylinder unle3s you replace everything the bobbin/plug as well.

You can buy just the bobbins but not locally.  You would need to contact the company that makes the vest.  For instance, Mustang lists them and shows Sportsman's Warehouse and Cabela's as dealers for their products.  But checking either stores website doesn't show they carry just the bobbin.  Also, I think (but don't know for sure) that the bobbins might be a universal fit for most brands.  Here is what the Mustang website shows for just the bobbins (click to enlarge):