Features: This product is made from high-strength aerospace aluminum. It is designed to maximize resistance to breakage, providing improved durability compared to the OEM fitting. The coolant flow path through the center of the fitting is optimized to enhance coolant flow. Additionally, the surface area of the coolant flow path is larger than that of OEM components, further improving cooling performance.This hose connects the coolant thermostat housing to the front of the engine head. The plastic fitting on this hose is a known weak point in the cooling system and is prone to cracking and leaking. The ideal solution is to replace it with a more durable fitting that will not crack, wear out, or leak. This fitting is a direct replacement for the stock plastic fitting and requires no modifications to the system.Made from high-quality aluminum alloy, this fitting is durable and wear-resistant. It features a smooth internal design with no sharp corners, allowing for unrestricted coolant flow. Built to factory original equipment specifications to ensure a proper fit.Installation is straightforward: remove the hose from the original plastic fitting, remove the old fitting from the head, install the new fitting into the head, then reattach the hose and hose clamp.Specifications: Material: Aluminum Alloy Length: Approx. 4.3 cm / 1.69 inches Color: Silver, Red, Black, Blue Fits: 3 Series N54 335i 335 (Part Numbers: 11537541992, 11537544638)Package Includes: 1 x Water Hose FittingNote: 1. Please allow 12 cm variation due to manual measurement. Ensure you are comfortable with this before ordering. 2. Due to differences in monitor displays, the actual color may vary slightly from the image. Thank you for your understanding.