Been following some of the M8 testing threads and looking at others as well. Was wondering what the best flowing AC that you can put a cover over is, whether it's the stock cover or something else. I have an 18 Road Glide Ultra that I'm going to put an S&S 475 in along with a D&D billet Cat. I've run open element breathers before but within a day or two after riding out in the sun they always look dry. I know they still have oil in them but it still bothers me. LOL I always keep a shower cap handy in case I have to park outside and it's raining, I was just thinking I would try a covered breather this time around just so it might have a little more protection from rain and such. I'm not doing heads or a big build but I don't want to lose anything by going to a covered one, if there is a noticeable difference then I'll run an open element again.