I liked this module for the following reasons: 1. Compact; 2. Possibility of control with eWelink "out off the box" or another if the firmware is changed; 3. Inputs (Key 1 to Key4) for local control or another external system; 4. Access to the serial interface by pins; 5. Easy to attach to 5V relay module (select module with option to select High / Low control by jumper).