Aluminum 36mm Water Cooling Jacket for M41 & Spartan Hot Racing 36mm aluminum -Full coverage water cooling jacket for the Traxxas M41 and Spartan boats Features: - CNC machined billet aluminum construction - Full coverage and machined cooling fins for increased heat transfer - O-ring seals for leak mitigation - Black anodized finish for durability, corrosion resistance, and great looks - Secondary processed machining exposes aluminum for enhanced aesthetics - Installs on Traxxas 36mm marine motor Includes: (1) aluminum cooling jacket Specs:- length: 63mm (2.5 inch) - Inner diameter: 36mm (1.4 inch) - Outer diameter:51mm (2.04 inch) - Weight: 3.2oz Note: - Replaces Traxxas factory TRA5760 rubber water cooling jacket