In my backyard has always been this sewer pipe with a brass lid on it. The brass lid is screwed into a white PVC adapter on the end of a vertical pipe. I've cut the lawn for 20 years and always ran right over this thing until today when the blade of the mower caught it just right and busted the PVC adapter to bits! The brass top got chucked about 20 yards, but it otherwise not too bad off. What I'm left with now is a vertical pipe - I think maybe it is 3". I went to Lowes and found another adapter that the brass cap would screw into, but the bottom of this adapter is the same size as the pipe so it won't fit over the pipe. The second thing I picked up is this thing called a test cap or something, basically it is red and fits within the 3" pipe, then you screw a metal screw that expands a rubber thing on the inside to lock it into place. Will that be a sufficient replacement? I think the original thing was sealed off well enough with the metal cap and this seems to accomplish the same goal.