They will take a little water but not alot.A friend of mine had one on his H-D & got caught in a rain storm.The next day I took the filter off to clean it up & the intake track was stained with dirty water proving that it was getting into the engine.He took it off & put the OEM back on.Can you ride in the rain with those things? I'm not the "get under the bridge" type of rider except to put on the rain gear.
Autozone sells them. My buddy has an open filter like that but his is pretty standard. Not shaped like a dagger. Either way he got a cover for his to block the rain. Not sure if they sell or even make covers to fit yours but it's worth a try.
K&N Air Filter Wraps