The Rheem RTG20128-2 Horizontal Termination is designed for 3 in. and 5 in. venting applications in Rheem tankless water heaters. This high-quality termination kit ensures proper venting and exhaust of combustion gases, enhancing the safety and efficiency of your heating system. Constructed from durable materials, it is built to withstand harsh environmental conditions. The horizontal termination is compatible with various Rheem models, making it a versatile choice for both residential and commercial installations. Easy to install, this termination kit is essential for maintaining optimal performance of your water heater.