1. Use of the original SMI type of double relay;
2. Input is two way to trigger, but there are four output;
3. Output of the relay has two public side, often beginning, often closed, and two independent work;
4. Use of high temperature resistance PA terminal, the quality is very good;
5. With a working state indicator relay;
6. With the SS8550 original transistor to do the switch tube, the big current is more quality assurance;
7. High level of the module is triggered, that is, with DC positive trigger.