A tank bag involves two separate compatibility checks: mount to motorcycle, and bag to mount. Check the exact model, model year and part number; a similar appearance does not establish compatibility.
For example, SW-MOTECH PRO bags do not fit EVO rings, or vice versa. In the PRO system, magnets guide the parts together while a mechanical latch secures the bag. This differs from a magnetic bag attached directly to the tank. The ring system is intended to keep the bag clear of the paintwork.
GIVI TANKLOCK instead uses a motorcycle-specific flange mounted at the fuel cap. When considering bags with magnets or straps, account for the tank material and any outer covers too.
Try the bag on the motorcycle before buying: steering and controls must move freely. Also check how it comes off for refuelling. Follow the particular kit’s fitting instructions; capacity in litres tells you little about mounting compatibility.