I'm no battery expert, but my understanding is as follows:
a "12 volt dc wet battery" is any lead acid battery that produces 12 volts dc and contains a liquid electrolyte, just like the sulphuric acid in a car battery.
a "92Ah sealed AGM 12V battery" is similar to the above, but instead of having liquid acid inside the battery it has a gelled electrolyte and the cells are separated by AGM (or Absorbed Glass Mat) dividers. This kind of battery won't spill electrolyte out if the case cracks for some reason. My understanding is that this kind of battery is relatively new technology and is superior to the "wet" lead acid battery.
The 92Ah means that the battery will store 92 amp hours on a single charge, and that simply tells you how much power the battery can store on a single charge, and that translates directly into how long the battery will operate the pump for. If the pump draws 4 amps say, a 92 Ah battery will operate the pump continuously for 23 hours on a single charge. The higher the Ah rating of the battery, the longer it'll be able to run your sump pump on each full recharge.
What you need to confirm are: are the terminals the same and will the new battery physically fit in the space occupied by the old battery. If so, then you're in business.
Ideally, you'd want to get a battery with a higher Ah rating than your existing battery. The greater the Ah rating of the battery, the more of a charge it will store and the longer it will be able to operate your pump on a single charge. This is not that important to compare between batteries. As long as the battery has the same terminals and will physically fit, then you can use it. The greater the Amp-hour rating of the new battery, the longer it will operate your sump pump between charges. You'll have to find out what the Ah rating of your old battery is.
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hope this helps.