Replacement CHEM-CAP® plug and control knob for CHEM-VAC™ high vacuum valves CG-951 through CG-960. Plug is sold complete with control knob and CHEM-CAP® stem. PLEASE NOTE: CONTROL KNOB IS NOT SOLD SEPARATELY ON THE CG-900 SERIES VALVE. THE 0-20mm BORE SIZE VALVE IS OUR PREVIOUS STYLE CG-500 SERIES VALVE WITH COARSE THREAD.