ITEM NAME:1A DC 5-40V To 3.3V DC-DC Step-Down Buck Converter For Arduino ESP8266 RF M B6V9 1A DC 5-40V To 3.3V DC-DC Step-Down Buck Converter For Arduino ESP8266 RF M B6V9 Description: Input voltage 5~40V,output 3.3V Maximum output current 1A DC-DC Step-Down Converter module working frequency 550KHz. efficiency is 76-90% . Quiescent current: about 1.5MA Overtemperature shutdown, input under-voltage protection, BS-voltage protection, and short circuit protection. 2.54mm pin pitch, Arduiuo UNO MEGA2560 Breadboard MCU Development Board friendly Excluding Pin Size 18.3mm x 10.2mm x 6.7mm( small) Weight : about 1.3g(Very light) Applications: 3.3V MCU ARM CPU FPGA/CPLD 12V 5V TO 3.3V lithium battery-