Please note: maybe there are some modules without ESP-01S logo like pictures show, it didn''t affect the function.
Latest version esp-01s,comparing to ESP-01, ESP-01S will provide you stronger antenna singna
1MB Flash Memory. upgraded from 512KB，Integrated WEP, TKIP, AES, and WAPI engines. 802.11 b/g/n
Wake up and transmit packets in 2ms. Standby power consumption of 1.0mW (DTIM3)
Document link: https://nurdspace.nl/ESP8266

Technical Details

Product Details

Product Dimensions

Package Dimensions
Width : 2.8 inch
Height : 1.1 inch
Length : 4 inch

Item Weight: 0.16 ounce (View shipping rates and policies)
Shipping Weight: 0.64 ounce (View shipping rates and policies)

ASIN : B01N98BTRH