This 5/16 inch safety access locking cap SFL51650 is professional tamper-resistant protection fitting designed for HVAC refrigerant service valves. Made of high-grade nylon PC thermoplastic material, it features outstanding UV resistance, corrosion resistance and extreme weather tolerance, maintaining stable performance under long-term outdoor and harsh working conditions.

Each pack contains 50 pieces of locking caps, perfectly designed for 5/16 inch valve fittings. Tool-free hand-tight installation allows quick and convenient assembly without extra equipment. Compatible with multiple common refrigerants including R12, R22, R134A, R404A and R410A, widely applicable to residential and commercial HVAC systems.

These safety locking caps effectively prevent refrigerant theft, unauthorized tampering and system leakage risks. They comply with local building code requirements and provide reliable protection against potential safety hazards such as inhalation injury. Resistant to grease, oil and solvents, they deliver long service life and consistent tamper-proof performance all year round.