The Shield™ refrigerant locking cap has an inner and an outer cap, which are made from C360 alloy brass. The cap comes with a waterproof, color-coded, rubberized sleeve to protect the cap against outside elements as well as allow for easy identification of refrigerants. It is machined to be opened only with a tamper-resistant bit that is available to licensed HVACR techs and electricians. The Shield Refrigerant Locking Cap meets International Mechanical Code (IMC) 1101.10 and International Residential Code (IRC) M1411.6 that require locking caps on all outdoor service ports.