Here's what we're working with, a 21/2-inch Stainless Works DIY Rod Builder Kit. The kit comes with a variety of tubes: four straight tubes, four 90-degree elbows, four 45-degree elbows, and four U-bends. Along with the kit we also ordered a set of polished oval mufflers, polished turn-down tips, a set of header collectors, and hangers. If your project requires more bends you can order them separately. A "grab bag" of bends containing random angles and lengths can be purchased as well.