This document introduces the features and characteristics of three models of pressure regulators: XR 63, XR 64, and XR 65. XR 63 is designed for low-pressure and small-flow process conditions, with small instantaneous pressure drop and high stability. XR 64 is suitable for medium-flow semiconductor manufacturing processes and has a relatively small size. XR 65 is designed for large-flow process gases and undergoes special purification treatment. All three models of pressure regulators have stable flow characteristics, smooth operation, and accurate measurement.