ITEM NAME:DC-DC USB step up/down power supply module boost converter 5V to 3.3V/ Cy.One button to turn off the output;. Input 1.2-2V,output power within 2W;. Input 2V-20V,output power within 3W;. Input 20V-24V,output power with in 2.5W;. Display:3Bit digital tube display;. Output power.