Aquacraft GrimRacer Water Cooling Jacket, 36/45mm FEATURES: Silicone construction fits around 1.4-1.8 (36-45mm) diameter boat motors and directs water around can surface for extremely efficient cooling INCLUDES: Water Cooling Jacket with two PVC Tubes REQUIRES: Placing around motor and installing cooling lines (standard size fuel tubing (GPMQ4131) can be used for cooling lines