This is Insulated Outdoor Wood Furnace & Boiler 1-1/2" PEX Pipe. In all our dual line piping systems there is a layer of insulation between the two pipes. The tubing is also approved for use with potable hot water and with ANY outdoor wood stove. Oxygen barrier tubing is recommended for all types of systems to prevent oxygen diffusion through the pex tubing. For closed systems an oxygen barrier is a must. For open systems it greatly reduces the amount of oxygen in the water which limits corrosion. As proven, oxygenated water causes aggressive corrosion of any metal. If you have a pump failure or mechanical problem which stops the flow of water in your pipe, this tubing will expand when frozen. It will not crack or break. It can even be placed above ground for mid-winter installations. This insulated pex piping is taped solid from one end to the other so that the insulation remains tight around the pex tubing and keeps your lines hot. Other manufacturers of pipe just tape down the seam and the insulation is loose around the pipe. The package consists of: a flexible 6" waterproof corrugated plastic pipe (see pictures) two 1-1/2" pex lines (one red, one blue pipe for easy identification) 5 wrapped low-E closed-cell foil-faced aluminum insulation (see pictures), fully taped from end to end, not just down the seam of the insulation like others do! a string line inside the 6" pipe for snaking anything else through the piping