Heltec LoRa Node Products Difference Table:  Heltec product family already included follow options:  LoRa spread spectrum communication (node);  Battery powered;  Good RF circuit design and impedance matching.  Product: Type MCU FLASH Battery Battery Detect Vext Low Power Display WiFi LoRa 32: Dev-Board ESP32 4MB Lithium x x x OLED (128x64) WiFi LoRa 32(V2).  (Product ID: 1639291): Dev-Board ESP32 8MB Lithium 800uA OLED (128x64) Wireless Stick.  (Product ID: 1639290): Dev-Board ESP32 8MB Lithium  800uA OLED (64x32) Wireless Stick Lite.  (Product ID: 1638098): Dev-Board ESP32-PICO 4MB Lithium 35uA x Wireless Shell.  (Product ID: 1638101): Module ESP32-PICO 4MB  x 10uA x LoRa Kit 151.  (This item): Dev-Board STM32L151CBU6 128kB Lithium x x 7uA x LoRa Node 151.   (Product ID: 1638100): Dev-Board STM32L151CCU6 256kB 1/2 AA Lithium chlorine sulfite battery ??? ??? 1.8uA x Turtle Board.  (Product ID: 1638099): Dev-Board STM32L432KC 256kB AAA x 2 5uA x    Notes:  Type:  Dev-Board, Can be used directly;  Module: Only core function, need to cooperate with external PCB or circuit.  Lithium: All lithium battery socket for Heltec boards is SH1.25-2;  Vext: 3.3V(500mA) output, for external devices (e.g. sensors) power supply, in deep sleep mode, Vext can be shut down via software;  Low Power: Products low power design, of Whole Circuit, the measured data are the current of the system during deep sleep.    Feature:  -In order to meet the user, requirements for Ultra-Low-Power and standard LoRaWAN protocol, we designed this product. On the basis of STM32L151CBU6MCU and SX1278 LoRa chip(433, 470MHz), the low power current can reach to 6uA.  -CE Certificate;  -Microprocessor: STM32L151CBU6 (Ultra-low-power ARM Cortex-M3 MCU with 128 Kbytes Flash), with LoRa node chip SX1278 (433MHz ~ 510MHz);  -Micro USB interface with a complete voltage regulator, ESD protection, short circuit protection, and other protection measures;  -Onboard SH1.25-2 battery interface, integrated lithium battery interface, integrated battery management system (battery power detection, USB / battery power automatic switching);  -Integrated CP2102 USB to serial port chip, convenient for program downloading, debugging information printing;  -This product supports DFU mode download (need to cooperate with relevant download software).  -System resource: FLASH 128K,  RAM16K,  EEPROM 4K;  -User available resources: FLASH 64K, RAM 8K, EEPROM 4K;  -Provide standard LoRaWAN protocol routines.  -With good RF circuit design and basic low-power design (sleep current ???7uA), it is convenient for IoT application vendors to quickly verify.  -LoRaWAN protocol easily.  Source: Parameter:  MCU: STM32L151CBU6 (Ultra-low-power 32-bit MCU ARM-based Cortex-M3).  LoRa chip: SX1278.  LoRa bands: EU_433, CN_470_510,two bands optional.  LoRa maximum output power: 18dB 1dB.  Hardware Resource: USART x 3; SPI x 2; I2C x 2; ; USB 2.0 x 1.  12 bits ADC; 12 bits DAC.  DMA controller.  28 general GPIO.  Flash: 128KB FLASH; 16KB SRAM; 4KB EEPROM; 80B BACKUP REGISTER.  Interface: Micro USB x 1; LoRa antenna(IPEX) x 1.  length x width x height(pin): 57 x 27 x 7(14) mm.  Battery type: Lithium.  Low power design: Deep Sleep: 6uA.