The Medinuclear/Marketlab RV-137-200U Reference E-Vial Source is a precision calibration source containing Cesium-137 (Cs-137) with an activity of 200 microcuries (uCi). Designed for nuclear medicine and laboratory environments, this reference source ensures accurate calibration and quality control of dose calibrators and radiation detection systems.Manufactured under strict regulatory standards, the E-Vial source provides long-term stability and dependable performance for clinical, research, and diagnostic applications.