This
SAVSW1212SGWaterproof, High Torque, High Voltage Coreless Digital Servo, 0.14 sec / 638oz @ 7.4VThis waterproof, steel-geared servo is perfect for Monster Truck and most Scaler and Crawler applications where a slightly taller servo can be fitted. Precision steel gears, stump-pulling torque, and waterproof to IP67 standards (operates for up to 30 minutes in water up to 3 feet deep).Features:Center aluminum with nylon composite top and bottom caseOperates directly on 7.4v without the need for an external BECPrecision ball bearingsSpecifications:Torque @ 7.4v - 46.0 kg/638 oz-inSpeed @ 7.4v - 0.14 sec/60 degWeight: 83g / 3.27ozDimensions L x W x H mm: 40.6 x 20.7 x 46.1s.