Features 1、This key module has stable performance 2、Can be inserted directly into due,Ideal for linking up to your Mini Breadboard banana pi etc,or others MCU PLD CPU ( AVR STM32 ARM PIC C51 NRF24LE1 CC2530 MSP430 STM8 FPGA CPLD etc.) 3、4‑button Common Cathode key module(When pressed output low level). 4、GND K1 K2 K3 K4. 5、Adopted of electronic components, and accuracy process, ensure for the durability. Specification Features: This module has stable performance. Can be inserted directly into due,Ideal for linking up to your Mini Breadboard for banana pi etc,or others MCU PLD CPU ( AVR STM32 ARM PIC C51 NRF24LE1 CC2530 MSP430 STM8 FPGA CPLD etc.) 4-button Common Cathode key module(When pressed output low level). GND K1 K2 K3 K4" 4 PIN OUT 2.54mm Adopted of electronic components, and accuracy process, ensure for the durability Specification: Working voltage: DC 0-48V GND K1 K2 K3 K4" 4 PIN OUT 2.54mm Size:12.7*33mm/0.5*1.3in Weight: Approx.3g/0.1oz Package list: 1 x 4 Button Key Module Package List