XERUN AXE 540L R2 System for Rock Crawler (COMBO) – AXE 540L-1400KV-R2 FOC System Xerun AXE series is a closed-system: Due to its advanced technology, HOBBYWING Xerun AXE ESC works exclusively with Xerun AXE brushless motor. Features: Word's First FOC brushless system for Rock Crawler. Field-Oriented Control for Super Linearity & High Torque & Extreme Silence. The chip-type magnetic encoder inside the motor guarantees consistency between three phases signals and always outputs the pure and precise signals indicating the rotor position. Polarity Protection: Yes. it is not a typo. No more "oops" moment. The chip-type magnetic encoder inside the motor guarantees consistency between three phases signals and always outputs the pure and precise signals indicating the rotor position. The waterproof and dust-proof design (*IP67 standards) allows the AXE brushless power system to be used in all weather & track conditions without any issue of damage caused to the system from water or dust. Damage to the vehicle caused by water, mud, or conditions should be monitored closely when running in muddy, wet, or adverse conditions. Intelligent torque output & speed closed-loop control for easy control, and consistent motor RPM under all loads. The adjustable drag brake & drag brake rate control with the maximum drag brake of up to 200% (that's near twice the drag brake of standard brushless power systems) can provide unprecedented parking capacity on slopes, with no jerky stops. The innovative built-in Bluetooth connectivity. allows users to read ESC data or update ESC firmware via a smartphone (installed with the HW LINK app). The motor with 4 poles & 12 magnets, featuring Hobbywing's "staggered pole" patent has zero cogging effect & torque ripple. It can work smoothly at low speeds. This greatly improves the manoeuvrability of rock crawlers at low speeds. The new sensor harness, which features the plug-and-screw design, has a silicone O ring inside. The new design & O ring not only provide a firm connection between motor and ESC but solve the "waterproof" challenge for sensor ports. The advanced and secure electronic switch features a waterproof, dust-proof, and shock-resistant design. Multiple protections: low-voltage cutoff, thermal, fail-safe (throttle signal loss), motor lock-up, and overcurrent.