Precise Sizing & Specs: Measurements provided in both inch and mm,please order the correct size. Durable black silicone rubber construction ensures a perfect fit for automotive, firewall, wiring, desk hole, gas pipe, water pipe, and drain applications. Versatile Application & Protection: Environmentally friendly silicone grommet protects wires, cables, plastic tubing, temp probes, plastic cables, and pipes from abrasion. Ideal for house siding, glass, cable bushing, wire plug, wood hole, plywood, tub parts, marine wire, metal panels, electrical appliances, spray systems, cylinders, valves, hydroponics, and irrigation. Premium Performance & Durability: Engineered for exceptional corrosion resistance, waterproofing, strong insulation, flame resistance, and aging resistance. Withstands extreme temperatures from -40°F to +482°F (-40°C to +250°C), ensuring reliability in harsh environments. Effortless Installation: The top hat design, combined with the material's inherent toughness, flexibility, and elasticity, allows for quick and easy snap-in installation directly into pre-drilled holes. Creates a secure, sealed barrier instantly. Secure Sealing Solution: Provides excellent elasticity and sealing properties for waterproofing and dustproofing holes. Effectively safeguards against damage from sharp edges on metal, plastic, or wood. Note: Please verify required drill hole and inner diameter sizes before purchase for optimal fit. 30 pcs 1/4" Drill Hole, 3/16" ID Black Silicone Top Hat Rubber Grommets