This is the Futaba BLS157HV High Voltage, Ultra Torque Servo.

FEATURES: Equipped with a brushless motor that lasts longer and operates
            smoother and faster than brushed motors with a greater resistance
            to jolts and vibration
          Aluminum center case section
          Same power consumption as brushed digital servos
          Dual ball bearings and samarium cobalt magnets
          One year limited warranty through Hobby Services beginning at date of
            purchase

INCLUDES: BLS157HV Servo with 0.83" (21mm) diameter round horn, 1.8" (45mm)
            diameter round horn, 1.5" (39mm) diameter four-point horn,
            1.2" (32mm) diameter six-point horn, instructions and mounting
            hardware

REQUIRES: Installing in model and connecting linkage

SPECS:    Speed: 0.14 sec/60° at 6.0V
                 0.11 sec/60° at 7.4V
          Torque: 430.6oz/in (31.0kg/cm) at 6.0V
                  513.9oz/in (37.0kg/cm) at 7.4V
          Size: 1.59 x 0.83 x 1.51" (40.5 x 21 x 38.4mm)
          Weight: 2.72oz (77g)
          Power Supply: DC 6.0 - 7.4V
          Horn Screw Size: 3x8mm

                                                                   jxs 06/27/11
                                                                         ir/jxs