Professional grade fragrance gauges allow you to customize your friction selection for the application at hand, a smart way to manage inventory. Features: 100 pressure tests - reliable operation and leak-free performance. OE Matching Materials - Vehicle specific designs of cast iron or aluminum depending on OE specifications. EPDM Rubber Components - Superior resistance to corrosion from heat and leakage. Easy installation - fully assembled; copper bleeder screws for sealing washers and mounting brackets. Smooth Operation - Critical areas are pre-lubricated with a high-temperature synthetic lubricant. Hole diameter: 3 cm. Inlet Thread Size: 38 - 24. Reader Thread Size: 38-24.