Power supply mode:USB powered by 5V or 3V button battery,(note that USB and button batteries cannot be powered at the same time, otherwise the button battery be damaged) Working voltage: 2.8V Working current:12mA Sleep state:Less than 1mA Product name:-054A digital tube display calculator kit Note:Shipped in pieces, the colors of accessories are random, no specification is accepted, and it not affect the use. Colour:As Shown Material:abs Size:PCB size:113x78mm Package Contents: 1 set x calculator DIY kit 1 x shell Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is 1-3cm.