This is the Hobbywing EZRun MAX6 V3 1/6 Scale Waterproof Brushless ESC. Compatible with 3-8S LiPo power, the MAX6 is a great choice for 1/6 and 1/7 scale vehicles like the XO-1, but is also suitable for various 1/8 scale heavy vehicles like the E-REVO and CEN GST-E Monster Trucks. It's the ideal option for high-end aggressively powered builds.