Once a year, outdoors only, and most people can skip it
Who needs it
Anybody storing or using this outdoors. The finish degrades under ultraviolet light and reproofing once a year prevents that.
Who does not
Anybody keeping it indoors. Indoor use needs a damp cloth occasionally and nothing else, ever.
What is in it
Enough for four applications, which is four years. A single kit is not an annual purchase.
