Line sets consist of two 15 feet semi-flexible copper pipes to connect the outdoor air conditioner or heat pump to the indoor evaporator coil. The 3/8" smaller tube is called the liquid line (LL). The 5/8" larger pipe is the suction line (SL), & both pipes are encased with 1/2" thick insulation.
The pre-flared fittings easily connect the tubing without soldering. They are manufactured per the American Society for Testing & Materials (ASTM) Standard Specification B280. This line set includes 18 feet of 14-4 AWG 600v wire for connecting the indoor evaporator to the outdoor unit.