Our smaller mechanical test tee plugs (the TTMP for people in the know) have been popular for years. Simple to use, no air pump needed, sets in seconds. Did you know that we also have larger size plugs as well? The 8" and 10" have had a port to fill the stack from below for a while now and we just introduced a 6" version! Put your plug in place just like the smaller size TTMP series you are a accustom to and then use a hose to fill the stack for test from the plug. Once done, drain out through the same hose.