A fire extinguisher is one of the most important items on a boat when it is on fire. I have a unit that has a gauge as well as a size that is larger than required on all of my boats. Every six months it should be checked for the charge level as well as turned upside down and tapped and agitated to make sure the powder has not clumped up in the bottom. I replace them every 4 years and then take the old unit and store it in the garage next to my current one in case one is not enough.
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