This motor speed controller allows the direction of a DC motor to be controlled using a pulse width modulated (PWM) DC voltage. With a back-up fuse, it can automatically break the connection and restore it automatically. With an LED indicator and a rotary switch, convenient to use. Suitable for many electrical devices. It is a practical module for controlling DC motor speed. color:green Material: PCB Power, Output: Max.2A Input voltage: DC1.8V,3V ,5V,6V,12V Item Size: 3 x 5.5 x 1cm / 1.2 x 2.2 x 0.4in Item Weight: 56g / 2oz Package List: 4 x PWM motor speed adjuster module Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.