This is the Hobbywing Xerun XR10 Pro 1S Sensored Brushless ESC. The XR10 Pro 1S is the ideal solution for competitive 1/12 scale applications and features a small, lightweight footprint, built-in electronic switch, super BEC, various programming methods and 120A continuous power. 

Compare 1S ESC

• ROAR | IFMAR approved 
• 40% smaller in volume* (*6mm shorter,  6mm smaller in width)
• 24% lighter in weight (12g lighter than the previous generation)
• Premium MOSFETs (Toshiba MOSFETs)
• Super BEC. Internal BEC features booster circuitry can output the current/voltage of up to 6A/6V and power various servos without connecting any extra receiver battery.
• Built-in electronic switch (with a lifespan of over 50000 on/off cycles, dust-proof and shock-resistant design)  
• Built-in capacitor module saves space and weight making the wiring simple and neat.
• PWM Frequency tuning - guarantees precise and accurate throttle and brake control for all classes of competitions (esp. the Stock class).
• Maximum Cooling performance - Separate Programming/Fan Port
  The separate PRG/FAN port on the ESC can power an external fan to maximize cooling performance or connect the ESC to an LCD program box or WiFi module for ESC programming.