I just bought a Buck 74 and when I started looking at everything I got, I see this ring that looks like it would be the flue collar. It came seperate, not in the box with the stove, it has a gasket on one side and 2 "L" bolts inside. This "ring" has 3 holes drilled in it for me to attach my stove pipe. The stove has a flue collar on it already with 3 holes for the pipe. The "L" bolts don't seem to attach to anything I have. I am using single wall pipe. Is this ring something I need or for someone that has a different setup than me?