... emitting colors 3.High brightness 4.Long life 7 segment LED digit display in blue color 4 digit Specifications: Size: 0.39 inch ... Voltage: 2.8-3.6V Wavelength: 462-470nm Various colors: blue, green ... : Different sizes are available: 0.24, 0.25, 0.31, 0.32, 0.36, 0.51, 0.56, 1.5, 1.8, 2.3-inch and more number ...