RCmall 3CH Digital Multi Servo Tester ECS RC Consistency CCMP Master Speed Controler Checker CCPM Servo Consistency Master / Servo tester. The 9g mini servo motor link: https://www.amazon.com/dp/B07456J6K3 The device also can be used as a signal generator for electric speed controller (ESC). With the multi servo tester, you can test your motor system without using a transmitter and receiver Input: DC 4.2-6.0v; Output: &lt; = 15mA (5.0); Output signal: 1.5ms  0.5ms Package included: 1 X Servo Tester. We offer life limited friendly customer service. Any problem please contact us feel free.