1PCS 3-8V Servo Tester Dual Port Reverse Connection with Power On Indicator Features: Microcontroller core, precise output. Unlike general servo control, this tester outputs 1000-2000us 50Hz PWM signal which is more compatible with general remote control output. With soldering point, it can be changed to 500-2500us output (can drive servo that can rotate 180 degrees). Can also test ESC (ESC is also driven by PWM signal). Double-row pin structure, two identical signal ports, convenient for power supply and testing. Suitable for 3-8V voltage, can be used with high voltage servo (2S lithium) (5V servo do not use 2S power supply). Power supply + - anti-reverse connection. With power-on indicator (light can pass through the case). 25x15mm weight 4g Instructions for use: Currently there are users testing on niche ESCs, saying that the motor can't be stopped when the throttle is minimised. (This is mostly the ESC travel is not right) description has stated that the device signal minimum value of 1000us (there are welding points can be changed to 500us) so your ESC can not be adjusted to travel range and this range of Don't buy this product if you don't know this range (using solder joints to set the minimum value to 500us may be useful, but I haven't tested it). Special instructions for testing ESCs without BEC Special note: 1. Only use battery, prohibit the use of regulated power supply. (Otherwise the tester may be burnt in a second by the instant high voltage generated outside during the rotation process, and you will get the same result if you change the servo tester of other brands). 2. 2S lithium battery, if the circuit is not right, the motor self-inductive superposition may also produce high voltage burn governor. Safe connection is as follows: from the negative terminal of the battery and 3.7V at the lead out of two thin wires connected to the governor + -; ESC single signal line connected to the governor signal (ESC signal overhang do not connect). Governor power consumption of a few milliamps, not likely to cause 2S lithium discharge imbalance. (Note: plus cap is too high, not compact enough) Some people ask: can control the air model ESC? Then the shop owner to ask: your ESC support PWM signals? If you do not understand, then if the general aviation model receiver can drive the servo socket can control your ESC, it means that your ESC support PWM. (Generally traditional ESCs support PWM. Special note is that bIhel i open source firmware ESCs support a number of protocols (e.g.: oneeshot), but also support PWM). Package includes: 1 * Servo Tester