30-Pack Radiator Bleeder Key Set: These radiator bleed keys are perfect for bleeding radiators and taps. Robust Material: Made from high-quality zinc alloy, these keys are sturdy and durable, preventing water leaks. Rust-resistant and practical, they are long-lasting and won't easily break. Easy to grip and turn, even after tightening stubborn valves. Square Opening Keys: Each key measures approximately 3 x 2.2 cm / 1.18 x 0.866 inches, with a 5 mm / 0.197-inch inner square edge and an 8 mm / 0.315-inch outer diameter. One size fits most radiators on the market. Precision Plating: These keys feature precision multi-layer plating, making them acid and water-resistant. They stay clean in humid environments for extended periods. The tight structure prevents explosions, ensuring safe use. Quantity per Pack: You receive 30 radiator keys, ideal for replacements and preventing central heating system breakdowns during winter. Lightweight and Durable: Easy to install and carry. A round hole on each key allows for attachment to a keyring for convenient portability, suitable for both indoor and outdoor use. Note: All data is manually measured, please allow 1-3cm error. Due to light and screen differences, there will be a slight color difference, subject to the physical item received.