No leftover packaging hey? Good deals always come at some cost
Have you tried comparing your filters with photos of ones on the internet? ZWO's a pretty popular brand....
Have you tried visually inspecting the filters? If you shine a torch through each one onto a white background, what colours do you see?
Have you tried taking some test photos with them? Could that help figure out which ones are the broadband, and which are the narrowband? Could said test photo's then be compared with an analogous spectrum image on the internets?
Bullets can be bitten, but taking that route everytime in this hobby will get expensive quickly.