ITEM NAME:5Pcs 5.5mmx 2.1mm dc jack socket plug power supply module CE BX Feature: Name: DC power adapter board Module Size: 2.8cm * 1.3cm Applicable connector: 5.5 * 2.1mm Power output interface: 2 channel VCC, 2 channel GND Package Included: 5pcs  5.5x 2.1mm DC Jack Socket Power Supply Module 5.5mmx 2.1mm For Arduino.Power output interface: 2 channel VCC, 2 channel GND. Module Size: 2.8cm 1.3cm.