Hitec HS-646WP Analog Waterproof High Voltage Servo HS646WP / HS646 / 646WP / 646 Receivers These couplers are interchangeable with

These couplers are interchangeable with Kadee 20

Hitec HS-755MG Metal Gear Giant Scale Servo

This is the Kadee Electric Under-The-Track Uncoupler Kit

Does not have battery failsafe function

Hitec HS-646WP Analog Waterproof High Voltage Servo HS646WP / HS646 / 646WP / 646 Receivers These couplers are interchangeable withHitec HS 646WP Analog Waterproof High Voltage Servo Our new waterproof servos have what it takes to keep your radio control vehicle, airplane or robot watertight! With high torque, dual ball bearings and metal gears, our analog waterproof servos have the industrys first IP67* rating ranking them among the most durable and reliable servos for wet conditions. Whether you are manning your power boat, bashing in the mud, directing your underwater robot,