Accurate flow measurement is best achieved with an optimized flow profile. All those involved in the design, implementation and operation of a custody transfer station benefit from flow profile standards of accuracy that far exceed those of the past 40 years. By including flow conditioning in their latest metering station design standards, the American Petroleum Institute (API), American gas Association (AGA) and ISO have recognized a technology that insures an unparalleled degree of flow accuracy. This technology is a High Performance Flow Conditioner—placed upstream of a flowmeter—which conditions the flow such that it enters the flowmeter with a uniform, non-swirling, fully developed profile. This happens regardless of the pipe configuration prior to the conditioner. Recent developments in High Performance High Performance Flow Conditioner technology have created a paradigm shift in the design and application of natural gas custody transfer metering stations. Whether it is Orifice Turbine or Ultrasonic applications, High Performance High Performance Flow Conditioners have brought increased accuracy and simplified installations to the industry at large. This paper discusses the high performance High Performance Flow Conditioner technology; it’s application and recent calibration results from a number of calibration facilities in North America. In addition the paper with discuss the integration of a High Performance Flow Conditioner with an Acoustic Filter element