HiLetgo 5pcs Micro SD TF Card Adater Reader Module 6Pin SPI Interface Driver Module with chip Level Conversion for Arduino UNO R3 MEGA 2560 Due The module (MicroSD Card Adapter) is a Micro SD card reader module for reading and writing through the file system and the SPI interface driver. SCM system can be completed within a file MicroSD card .Support Micro SD Card, Micro SDHC card (high speed card). 3.3V regulator circuit: LDO regulator output 3.3V for level conversion chip, Micro SD card supply. Level conversion circuit: Micro SD card to signal the direction of converts 3.3V, MicroSD card interface to control the direction of the MISO signal is also converted to 3.3V, general AVR microcontroller systems can read the signal. Positioning holes: 4 M2 screws positioning holes with a diameter of 2.2mm, so the module is easy to install positioning, to achieve inter-module combination.