This is the BLC-30C 30A Car Sensorless Electronic Speed Control from Ace RC.

FEATURES: LiPo programmable low voltage cutoff
          Ideal for 1/10 scale on road RC vehicles using brushless sensorless
            motors up to 3500kV
          Automatic initial programming
          Reverse with programmable reverse lockout for racing
          Propotional braking
          Program card for easy adjusting of parameters
          Anodized aluminum heat sink

INCLUDES: BLC-30C 30A Car Sensorless ESC with Tamiya type Battery Connector,
            three 4mm Female Bullet Motor Connectors, Capacitor, On/Off Switch,
            Universal Receiver Connector, Cooling Fan, Program Card,
            Instruction Sheet, and three 4mm Male Bullet Connectors

SPECS:    Continuous Current: 30A
          Input Voltage: 6V-7.4V (2S LiPo)
          High Temperature Protection: Yes
          Motor Limit at 7.4V: 540-3500kV
          Pulse Frequency: 1KHz
          BEC: 5V @ 2A
          Dimensions: 1.5 x 1.2 x 0.75" (38 x 32 x 19mm) w/o cooling fan
          Weight: 1.76oz (50g)

                                                                   jxs 12/04/12
                                                                         ir/jxs