[Sizes]: 3-inch straight fitting with 3/4-inch hose connector and 1/2-inch water pump pipe threads; 1-3/4-inch straight fitting with 5/8-inch hose connector and 1/2-inch intake manifold pipe threads. [Stainless Steel Construction]: This heater hose nipple is made of Metal, offering excellent resistance and high-temperature performance, ensuring durability in harsh engine environments. Its superior sealing prevents leaks while providing excellent mechanical strength. [Compatible Models]: This heater hose nipple is suitable for series engines: 283/305/307/327/350/383/400. [Easy Installation]: First, the engine is cool. Remove the old fitting, clean the connection point, and inspect the hose for wear. Apply lubricant to both ends of the fitting. Align the hose with the component and push it fully into place. Secure with a clamp and tighten. Finally, refill the coolant and perform a leak test. Please note: Actual product color or appearance slightly, but this does not affect functionality. Thank you for your understanding! Color: As Shown Material: Metal Package Contents: 1set x Heater Hose Fittings Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.