This project evaluated current end treatment designs that are used in the natural gas industry and used Computational Fluid Dynamics (CFD) to determine the end treatment with the best flow characteristics when installed upstream from an ultrasonic flow meter. The project team optimized the end treatment design and additional CFD and experimental testing was conducted. The experimental results of the developed end treatment were shown to provide results within ±0.25% relative to the baseline configuration with various inlet conditions and numbers of ultrasonic paths.