RS-44b (R453a) is the newest R22 drop-in replacement refrigerant in the U.S. market. RS-44b has been sold worldwide for the past 5 years, branded as
RS-44 - RS CoolRS Cool
Replacement for R22 - Replacement For R22
RS 44b Drop-In Replacement Refrigerant for R22 Overview
RS-44 - RS CoolRS Cool
What is RS44b ( R453a ) Refrigerant and Should You Use It?
RS-44b Refrigerant, 24lb. Cylinder
R-453A / RS-44B R-22 SUBSTITUTE
Anyone Try Rs-53 As A Drop In Replacement For R410a?, 50% OFF
Replacement for R22 - Replacement For R22
Comstar® RS-44b Refrigerant, Drop In Replacement for R22
Chadwell Supply. R-22 Replacement Refrigerant Options