Thanks Mudhen, I measured the one they sent me and it is 1 1/2 inch. I emailed Rhino to see if they knew of any problems but haven't heard back from them yet. The problem appears to be that it is making contact the first place it flares on the bottom of the tube. I'll get it corrected, did take a gobbler at 35 yards with the SBE II and Comp-n-Choke combo on Tuesday. Thanks for the help.