Check the listing for details. HVAC Tools, Locking Cap Key for Refrigerant Safety Caps, Universal. Condition: New. Listed at 22.99 USD. The product is a universal locking cap key designed for refrigerant safety caps. It is a metal tool with a keyed lock mechanism, specifically made for HVAC systems. The key is compatible with various brands and models, offering a secure way to access and safely remove or install refrigerant caps. With a weight of 0.02 kilograms, this tool is a practical addition to the HVAC and refrigeration industry for professionals looking to ensure proper safety and functionality of refrigerant systems.