This mounting system uses a unique part called Nutsert. Basically it's like a drywall anchor for metal applications. You put it in the holes on the body and then screw in the screw. When tightening the screw, the back of the anchor should be pulled against the inside of the housing. Sounds like a great idea, and it might have worked if it wasn't for a cheaply made, poorly designed piece of junk. The problem is that the anchor itself rotates in the body, so it will never be able to tighten the back of the anchor firmly. The flange on the front is only about 16 inches thick, and the special tool that comes with it completely covers it, so you can't pinch it with pliers or anything to keep it from turning. It's perfectly round, so there's no way to use a ring spanner to fix it. I tried making a notch in the flange with my dremmel in hopes that I could stick a flathead screwdriver in it, but to no avail. I went to the hardware store, bought some JB Weld Epoxy and glued these little bastards in place with more epoxy. I'll let it heal overnight and tomorrow I'll try again. I hope my neighbors didn't call the police because I cursed and threw tools. Oh, and to top it off, you need to torque the bolts to 20 pounds. You work in a confined space. Torque wrenches are not small at all. Someone might sell a smaller torque wrench, but I won't buy a $150 tool because DZ won't spend an extra 50 cents to build a decent anchor system. If you have a welder and are reasonably decent and can do a few tack welds around the edges of the flange you can probably solve the problem fairly easily. I don't, and again, I'm not going to buy a welder to solve a problem for 50 cents. Shame on you, DZ.