They work with pipes between 55mm and 180mm in diameter, those commonly used for mains installation. The holding rings rotate to preset positions of 45 degrees and 90 degrees to allow elbows to be held. Liner shells clip in and out of the holding rings to allow different diameter pipes and reducers to be held and rerounded. The three way tool has an additional leg that allows tees to be held. These tools are completely adjustable making them versatile for every installation.