The male end is a bubble flare (as stated in the product description) and the female end is a reverse flare (which is not stated anywhere). that would be good to know. I was lucky enough to have a drill press with a vise and a brand new drill bit, I couldn't imagine hand drilling it. It would be great to include photos of both mating surfaces to show the type of mating and/or reference both surfaces in the description. I'm only giving 2 stars because I was able to pierce it to get it working. Very disappointed with this purchase.