Item Type: Water Cooling Jacket Material: Aluminum Alloy Product Length: Approx. 50mm/1.9in Inner Diameter: Approx. 40mm/1.6in Color: Purple Application: for RC Remote Control BoatPackage List 1 x Water Cooling Jacket Manual measurement, please allow some error. 1High Performance: The copper pipe is water cooled to dissipate heat, which makes the motor work longer. 2High Quality Material: Made of high quality aluminum alloy material, wear resistant, durable, and environmentally friendly. 3Good Heat Dissipation: It has good heat dissipation performance and is a perfect motor water cooling jacket. 4Easy to Use: Exquisite workmanship, female thread design, easy installation and disassembly, practical accessories. 5Applicable Products: Marine motor water cooling jacket, suitable for RC remote control boats with a diameter of 40mm.