SAE 20R3 Class D-2. SAE 20R3 Class A. [Size] ID: 3/4" (19mm), tolerance is ±0.6mm; OD: 1.10" (28mm), tolerance is ±0.8mm; Length: 50 feet. [Application] Used in hot water heater, engine's cooling system, connecting the radiator to the overflow reservoir, etc.
