Steel Dragon makes these dual types and an all in one type box as well. They mimic the old style boxes from the 70's , but are made with high quality aluminum and machining. Tuning for these boxes really wasn't that hard. I also am running a 4-2-1 Cycle X exhaust on the outlet side. I don't have any weird flat spots in the RPM range or anything. I'd recommend them as a nice alternative for those going for the look of something like pods, but the function of a stock airbox.