I havn't the foggiest, maybe their customers buy from other sources, or maybe they dont need them. I'm not trying to say dont buy their kit, it seems like a real good bargain, just that I would be worried about running calipers with no dust boots for long term street duty. I dont know what thier kit costs, but even if it's only 1200 you'd still expect it to last the life of your car. the dust boots would give me more peace of mind. weve all seen what brake dust does to wheels if you dont clean it off. imagine it sitting on those caliper pistons for a few years (if you dont drive the car much)