1-1/4 Inch Copper Rolled Tubing, 60 Foot Length - Type K. The tubing measures 1-1/4 Inches nominal size with an outside diameter of 1-3/8 inches. It comes in a 60 foot roll which makes it great for larger applications that require a longer distance of tubing or just more of it. It is important to note that this tubing will use 1-1/4 inch fittings such as, Copper (soldering required in most cases), Flare, Crimped/Pressed (power crimper necessary) or Compression connection fittings. This particular copper tubing is type K, which has the thickest walls of all copper tubing in the United States. Its thickness allows it to be buried, even under a street or sidewalk due to it being able to withstand more pressure. Note: Before burying copper tubing, it is necessary to know what is required per code. In most cases a polyethylene sleeve or a protective coating is required for burying copper tubing. Copper tubing applications may include a refrigerant line in your Heating, Cooling and Air Conditioning (HVAC) System or as supply lines for hot and cold tap water.