Makerfocus 4pcs ESP8266 ESP-01S WiFi Serial Transceiver Module with 1MB Flash for Arduino

Feature:SDIO 2.0, SPI, UART32-pin QFN packageWi-Fi Direct (P2P), soft-APIntegrated TCP/IP protocol stackIntegrated TR switch, balun, LNA, power amplifier and matching networkIntegrated PLLs, regulators, DCXO and power management units+19.5dBm output power in 802.11b modePower down leakage current of lt;10uAIntegrated low power 32-bit CPU could be used as application processorSDIO 1.1/2.0, SPI, UARTSTBC, 1 times;1 MIMO, 2 times;1 MIMOA-MPDU A-MSDU aggregation 0.4ms guard intervalIntegrated RF switch, balun, 24dBm PA, DCXO, and PMUIntegrated RISC processor, on-chip memory and external memory interfacesIntegrated MAC/baseband processorsQuality of Service managementI2S interface for high fidelity audio applicationsOn-chip low-dropout linear regulators for all internal suppliesProprietary spurious-free clock generation architectureThe PCB layout has changed for an improvement in WiFi radio performance.   Packing List: 4 * ESP8266 ESP-01S WiFi Serial Transceiver Module