Thimble Wall Double B-Gas 4in

I bought 2 of these wall thimbles for a dual tankless (EZTankless) water heater install. Why dual? Where I live, the water outta the tap is 42 degrees. You'll only get a 35 degree rise at best from one tankless, so you need to feed one into the other to get up to shower temperature of 105.The hole is 4 -5/8" (air-gap around that is 6-5/8"). I believe this is for clearance. You're just not going to get your 4" exhaust pipe "dead nuts on" lined up, so you need clearance. I just got some scrap metal vent material, and made some flanges. Cut a 6" circle, then cut a 4 -1/8" hole outta that, slide the flange up snug to the thimble, add 4 metal screws, put some of the supplied metal duct tape on for an air-tight fit - done! Flanges really should be supplied with this kit. If you don't have a pair of tin snips, and some scrap lying around, I've seen these for about $4 at the local hardware depot (but they are square, so you'll still need the tin snips if you want a professional looking install). You'll also need 1/2" sheet metal screws, and other 1" screws, or if your going up against drywall, maybe some drywall anchors etc. a power hand drill, and jig saw, etc.

Product was not as described and shown. It’s not two interlocking pieces. It’s just one side. I ordered this and returned it as missing parts only to get the exact same thing as a replacement.