The PTP-1 instrument test port consists of a ZAMAC (zinc) alloy body casting, which is installed over a sponge neoprene gasket and is red in color, making it easy to locate when conducting pressure/velocity tests. This housing is internally threaded to accept a precision molded high density polyethylene plug, fitted with a neoprene "O" ring, rendering it leak-proof. It withstands continuous intermittent operating temperatures of 165 deg F (72 deg C) and 215 deg F (100 deg C). Port cap has exceptional dimensional stability and is impervious to most chemicals and freezing temperatures down to -94 deg F (-70 deg C).