If you receive different versions module, please carefully follow the pictures and youtube video to test. Thanks!. Model: Esp-01.Compatible with Ar duino. Support 3 modes: AP, STA, AP + STA. Link to view the technical details and Introductionl: Please get the link from the below. Version II to test this module youtube tutorial and the Link to view the technical details, Please get the link from the below. Note:The test template tutorial is available in the product guide . There are a batch of this ESP01 modules are the new grade version. Maybe there are some different between the new one and old one in the aspect of usage. Pls feel free to email us if you have any question about how to use the new vertion module. How to email us? Click "MakerFocus" and click "Ask a question". There is the way to guide you to use the new version in the pictures, pls refer to the pictures carefully.