these are made for the DIY with a mig (using the right stainless set up) or tig welder who wants to do his own system, but doesn't want to suffer making these things because the are a pain. the runners are 2.25" and are about 4" long. they can be butt welded or stretched to slip fit up to 2.5" tube. just select the one you want from the drop down menu. thanks for supporting Monkey Fab!