Features 1、The module is designed for dialing keyboard and MCU interface. 2、Can instruct MCU(or keyboard) to generate 16 dual tones from Audio 1/2. 3、The DTMF module equipped with two 3.5mm audio plug for same times using. 4、Wide voltage range,you can connect it with voltage from 5~24VDC. 5、There are 7 MCU input interface on the module. Specification Features: The module is designed for dialing keyboard and MCU interface. Can instruct MCU(or keyboard) to generate 16 dual tones from Audio 1/2. The DTMF module equipped with two 3.5mm audio plug for same times using. Wide voltage range,you can connect it with voltage from 5~24VDC. There are 7 MCU input interface on the module. Specifications: Material: PCB Working voltage: DC5-24V Working current : 6-8mA Item weight: 16g / 0.56ounce Package weight: 20g / 0.71ounce Package size: 63 * 40 * 13mm / 2.48 * 1.57 * 0.51in Packing List: 1 * DTMF Module Package List 1 * DTMF Module