When buying a battery for a car or bike it helps to know the manufacturers casing type. This defines the dimensions pretty accurately between different manufacturers.
Our old Merc uses Type 019 casing - You can find a wide range of batteries in terms of Wet acid,Gell,AGM,Ah, cca etc - they will all phyiiscally fit in the battery space in the boot.
Finding the original manufacturers type can be quite tricky as they often want you to only buy one from them The closest I could find to a battery type for my 400 was
Type YB12A-A.
If you look on the Tanya website and go to the motorcycles section down the left side all the casing types are listed. In some instances there have been minor amendments to casing types to reduce casing manufacturing costs. So a battery that only has a small difference in say height for a partiicular model will show the one that fits even though its a mm less in height.
https://www.tayna.co.uk/motorcycle-batteries/ Julie has shown the options - I've gone for the long winded explanation as I am an overthinker.
