ESP-03 ESP8266 serial WIFI

product description
Features:
SDIO 2.0, SPI, UART
32-pin QFN package
Integrated RF switch, baluns, 24dBm PA, DCXO and PMU
Integrated R ISC processor, on-chip memory and external memory interface
Integrated MAC / baseband processor
Service Quality Management
I2S interface for high-fidelity audio applications
On-chip low voltage regulator for all internal power supplies
Proprietary spurious clock generation architecture
Integrated WEP, TKIP, AES and WAPI engines
product information
Package size 4.2 × 2.8 × 0.1 inches
Product weight 0.32 ounces