4404 Replacement Cartridge Silver, 24 Gram with Bayonet

I have been using inflatable life vests mostly for sailing, until I figured out they were ideal for kayaking too, because they are lightweight and less bulky than a typical life vest. And I have never inflated one. That is, until my wife rolled her kayak in two feet of water while launching from a steep river bank. Then I discovered how much it cost to replace the cartridge! We kayak weekly, so I bought two, so I’d have a spare. That was a smart choice, because two weeks later, she rolled it again, trying to land the kayak on a steep bank. So buy extras. I also bought extra bobbins, but despite having some vests for 10 years, the bobbins were still in good shape, and it wasn’t necessary to replace them. Nonetheless, you should always have an extra set. I don’t know if there are other brands, and I’m not comparing them anyway. This seems to be the standard brand for which most vests are made, so just buy it.