Refer to the digit display used in gas station to show gas price, always one station has one high bracket set up in outdoor ,
which double sides display the gas price . And each side has 5 groups numbers. Each group number has 4 digits like
88.88 . In this way , one big bracket has 10 groups( pcs ) of 4 digits display . We always call it one set =10pcs .
One gas station need one set .