Standard Size digital standard servo. Waterproof.  485 oz torque at 6.8 voltWeighs 2.12 ozSize 40x20x40.5mm. 1.58x0.79x1.60 inI DO NOT KNOW IF THESE ARE 7.4 volt Compatible. Packaging states 4.8 to 6.8

DS 8135 Hi Torque Waterproof Digital Servo

$32.95Price