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

Feature:
SDIO 2.0, SPI, UART
32-pin QFN package
Wi-Fi Direct (P2P), soft-AP
Integrated TCP/IP protocol stack
Integrated TR switch, balun, LNA, power amplifier and matching network
Integrated PLLs, regulators, DCXO and power management units
+19.5dBm output power in 802.11b mode
Power down leakage current of lt;10uA
Integrated low power 32-bit CPU could be used as application processor
SDIO 1.1/2.0, SPI, UART
STBC, 1 times;1 MIMO, 2 times;1 MIMO
A-MPDU A-MSDU aggregation 0.4ms guard interval
Integrated RF switch, balun, 24dBm PA, DCXO, and PMU
Integrated RISC processor, on-chip memory and external memory interfaces
Integrated MAC/baseband processors
Quality of Service management
I2S interface for high fidelity audio applications
On-chip low-dropout linear regulators for all internal supplies
Proprietary spurious-free clock generation architecture
The PCB layout has changed for an improvement in WiFi radio performance.

Packing List:

4 * ESP8266 ESP-01S WiFi Serial Transceiver Module