Uniweld 40061 Sludge Blaster® is great for unclogging a 3/4 Inch to 1 Inch condensate drain line without having to access the drain pan located in the A/C System's Air Handler. With the use of Nitrogen, CO2 or water the Sludge Blaster® expands inside the pipe and exerts pressure blasting the clog and sludge free from the drain line. Three Easy Steps: 1.) Insert Sludge Blaster® into Tee connection at the air handler, 2.) Allow nitrogen (Maximum 140 PSIG) to flow through, blasting the clog and sludge free from the drain line. 3.) Replace PVC Cap on Tee connection. For future service: Do Not Glue Permanently.