Built-in USB to TTL Transfer chip. Designed to be used for USB to TTL electronic projects. TTL interface output, easy to connect to your MCU. Status LED. Dual 3.3V and 5V Power output, work with 3.3v and 5v target device. - Size: 55mm * 16mm - Server 2008/Win7/Win8 32 bits / 64 bits. 1. support WINDOWS 98/ME/2000/XP/Server 2003/VISTA / 2. 3 V3 and 5V by a short circuit risk selection; 3. not only has the power light PWR, there TXD and RXD indicator, whether the product is easy to learn and intuitive to work in the absence of the instrument in the case; 4. high-quality high-grade yellow pin, pin durable than the black market, beautiful; 5. new original CH340G chips, the chips are recommended STC official USB to TTL chips will not appear due to different driver / different computers as a result of incompatibilities. CH340 module/ USB switch TTL/ USB transfer RS232/ over PL2303/ STC downloader/ 9 Brush board STC official download chip. Perfectly compatible with all Series MCU STC will not be because of the different drivers that would lead to problems like PL2303 can not download the program. Ultra-stable.