ITEM NAME:Water Cooling Jacket for 2030/2040/20mm Brushless Motor RC Boat Spare Parts Description: - Inner Diameter: 20 mm - Outer Diameter: 25 mm - Length: 25 mm - Inlet/Outlet Diameter: 3 mm - Application: for 20mm diameter brushless motors Package Included: 1 Pc Water Cooling Jacket Note: Please allow 1-3 mm error due to manual measurement. Color might be slightly different due to the color calibration of each individual monitor..1 Pc Water Cooling Jacket.