Sounds like a really daft question again! We've just bought a diamond leisure battery and new charger. Is this a sealed battery? As charger has a switch for normal/sealed
If it has removable plugs in the top, it is not sealed and the fluid levels in each cell will require checking occasionally.
If it has no visible means of removing anything from the top of the cells, it is sealed
I had a batery some time ago which did not have individual plugs, but one large molding strip with the plugs hanging from it. At first glance it could look like a sealed battery, but wasn't.
What was it advertised as? or google its reference.