The UVP-747/757 is 0.7 inch (17.22mm) height 5X7 dot matrix display. Single color display have the choices of three bright colors-AlGaAs red/green/yellow. All device have gray face and white dot. The AlGaAs red LED chip are made from AlGaAs on a non-transparent GaAs substrate. The green LED chip are made from GaP on a transparent GaP substrate. The yellow LED chip are made from GaAsP on a transparent GaP substrate.