The HY-40R201C with Wireless Modules Module RoHS is a wireless module made by Shengrun Technology Co., Ltd. It uses an SSL or Bluetooth protocol interface and is based on the WL18xx series. This module is compliant with the Restrictions of Hazardous Substances (RoHS) directive, so it is free of hazardous materials like lead, mercury, and cadmium, making it safe for use in a variety of applications. It has a high-speed UART interface and is capable of supporting up to three simultaneous connections. This module is designed to be used in a wide variety of applications, including home automation, industrial control, and automotive. Its low power consumption makes it suitable for applications that require battery power.