These fittings were designed to allow the installation of Stainless Steel Tubing, to solve tight applications and allow a cleaner appearence. When using excessive stainless tubing you may loose up to 20 percent of effiency of the air conditioning unit.
P/N 15020 -6 O'ring to 5/16' tube
P/N 15030 -8 O'ring to 3/8" tube
P/N 15040 -10 O'ring to 1/2" tube