1 inch Aluminum Hose Plug with NPT Female Port 89 The 41mm ID at one

The 41mm ID at one end and 35mm ID at the other end let you connect a 1 5/8" OD tube to a 1 3/8" OD tube

It is designed specifically for connecting 2" (51mm) OD metal intake pipes

but the clip-retained hose often leaks where it meets the reservoir

Use a standard heat gun to shrink the clamp tightly over the hose

5mm wall thickness (94mm / 3 11/16" OD) and a working pressure rating over 12 psi (64 psi burst pressure)

1 inch Aluminum Hose Plug with NPT Female Port 89 The 41mm ID at oneThese special plugs make it easy to add a switch or gauge sender to your cooling system. The 1 inch OD fits into the branch of any of our Silicone Coolant Hose Tees (sold separately). The female NPT threads accept a temperature or pressure switch*, an electrical gauge sender, or even a petcock to bleed air out of the system. Black anodized aluminum for long life. * Note: Grounding type single wire switches will require the addition of a grounding wire