The RASTKY Brake Bleed Screw Caps Resistant PVC Dust Cap is a must-have product for car brake system professionals. This set includes 20 caps, each designed to fit a 6mm screw hole, offering an efficient and secure solution for dust and moisture prevention. The RASTKY caps are made of PVC material, which is resistant to heat, cold, and chemicals, ensuring long-lasting durability and reliability. These caps are also resistant to abrasion, making them perfect for frequent use in demanding environments. Moreover, the screw top design makes it easy to tighten and loosen the cap, ensuring a perfect seal around the screw. The blue color of the caps adds a touch of professionalism and visual appeal to any brake system repair or maintenance project. In short, the RASTKY Brake Bleed Screw Caps Resistant PVC Dust Cap is a reliable, durable, and cost-effective solution for anyone working on car brake systems.