CO2 Stem is the inlet that attaches to the CO2 tank. The thread is left hand thread as is most common with high pressure valves.
California Residents: Prop 65 Warning
This product will be shipped with Prop 65 Warning to all California shipments.
WARNING: This product can expose you to chemicals including Lead is known to the State of California to cause cancer, and Lead, which is known to the State of California to cause birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.