This refrigerant line set consists of two semi-flexible soft copper tubing pipes to interconnect the outdoor condensing unit or heat pump with the indoor air handler or cased coil. the smaller in diameter is the liquid line and the larger one is called the suction line. This set includes the insulation foam 3/8" thick necessary to insulate the suction line which meets or exceeds most county and code requirements. COPPER REFRIGERANT LINE SET is 15 ft. in length and fully assembled, Both liquid and suction line sets are pre-flared for quick connection. I bought 3 each for $75 and used 2. Will sell for $40 or will trade. If interested e-mail me.