Brass control flow Lab safety faucet. 19mm thread NPT. Justrite self-closing Safety Faucets incorporate an internal flame arrester which prevents flashback of fire into the drum. Brass and stainless steel faucets feature a Polytetrafluoroethylene (PTFE) seal. Adjustable models screw tightly into drum and can be adjusted to dispensing position, with spout downward, without thread damage or leakage. Faucet extensions provide extra dispensing accuracy and prevents spills.