The Tranquility® (SH) Vertical Stack Chassis Replacement Series offers an innovative, labor-saving solution for spaces where individual, quiet control of the heating and cooling system is important. The Tranquility SH consists of replacements for multiple existing chassis series, including: 816, 817, TRM, and TSM/TSL Rev A-C. Using R-454B, a low-GWP refrigerant, the Tranquility (SH) not only protects the environment but also delivers unprecedented comfort, efficiency, and reliability.