This is the Hitec HS-75BB Retract Servoused for RC Aircraft Mechanical Retracts.with a Universal Futaba J, Hitec S, JR and Airtronics Z connector. FEATURES High torqueTravels 180 - full-lock to full-lock - to hold your gear in positionsecurely. Not proportional. Perfect for mechanical retractinstallation.Water resistantBall bearings INCLUDES Hitec HS-75BB Servo wUniversal connector, full set of horns,grommets, bushings and mounting screws SPECIFICATIONS Length (Not Including Mounting Tabs): 44mm (1.7)Width: 23mm (0.9)Height of Servo Case (Not Including Spline): 25mm (1.0)DistanceUnderside of Mounting Tab to Bottom of Servo: 16.7mm (0.66)Weight: 35g (1.23 oz.)Torque: 6.6 kg-cm (92 oz-in)Speed: 0.5 sec60 COMMENTS A retract servo is a very specialized servo. It is non-proportional,going 180 degrees, lock to lock. They are specifically made formechanical retracts to lock the gear in the up and down positions.they DO NOT have any means of end point adjustment and can not beadjusted by ATV on a transmitter. They are only able to go 180degrees and provide full maximum available torque at the two endpoints. This is their whole purpose and intentional design, but ifsomeone has a unique design situation where they need other than180 degrees available, then they must use a proportional servo,not a retract servo. They are specifically designed to withstandconstant holding loads in the up and down positions, unique to theuse of mechanical retracts.Pneumatic retracts do not need a retract servo. A proportionalstandard or mini servo is used to move the air valve back and forth For Gear set, order HRCM6343
