Novent refrigerant caps are precision machined from high grade brass surrounded by a protective aluminum shroud and can only be installed and removed with a special tool. Refrigerant cap mutikey unlocks all caps. Multikey for Novent refrigerant caps are easy to use. Key is used by certified HVAC technicians. Unlock Novent refrigerant caps for easy maintenance and public protection. Corrosion resistant locking key multikey. Can by used for all types of Novent refrigerant. FOR THE TRADESMAN: RectorSeal is recognized as a leading provider of quality solutions for the professional trades serving heating, ventilation, and air conditioning (HVAC/R), plumbing, electrical, and construction markets.