Production and performance of RE4 Resistive Plate Chambers for CMS experiment upgrade

The fourth trigger station composed of 144 Resistive Plate Chambers (RPCs) is currently being constructed to enhance the efficiency of muon triggers in the end cap regions of the CMS detector. All new CMS end cap RPCs gaps are produced in accordance with QA at Korea Detector Laboratory in Korea. The qualified gas gaps passing QC have been delivered to three assembly sites; CERN in Switzerland, BARC in India, and Ghent University in Belgium for the RPCs detector assembly. We report the status of the detector production and performance of RE4 RPCs including the sophisticated test procedures for the selection of qualified detectors.