Description: High quality aluminum material, sturdy, anti-corrosion and durable. Retainer cord included.Easy to install and replace. They prevent dirt and/or other materials from entering your tank valves between dives. Resist salt, sediment buildup, corrosion and damage from normal use. The dust plug is vented so that the presence of high-pressure gas does not trap the plug, making it difficult to remove. Specification: Material:Aluminum Alloy Thread Outside Diameter: Approx. 2.3cm / 0.91 inch Thread Inner Diameter: Approx. 1.4cm / 0.6 inch Top Diameter:Approx.3.2cm/1.26inch Height: Approx. 2.5cm / 0.98 inch Package Includes: 1 Piece Tank Valve Dust Cover (4 Pack) Note: Please allow slightly difference due to manual measurement. Color may be slightly different since different monitor. Thanks!