The wavelength of LED lighting is a physical quantity that determines the color of an object's light emission. LED light emitting tubes with consistent wavelengths emit light in the same color, which is known as good color purity. A lighting fixture is composed of multiple LED light-emitting tubes. Choosing LED tubes with the same wavelength will increase the cost. However, by relaxing the requirements, most users are not aware of the decrease in the color purity index of the lighting fixtures, and of course, the production cost has also decreased, which can be sold at a lower price. In addition, if color consistency is required, it is difficult to screen LED light-emitting tubes without an LED spectrophotometer, and purchasing a spectrophotometer will increase production costs.

The light-emitting body of LED is a chip, and different chips have significant price differences. The commonly seen chips in the market now include chips from Japan and the United States, as well as LED chips from local manufacturers in Taiwan and China. Due to the high cost of chips in Japan and the United States, their prices are naturally higher than those of LED chips in Taiwan and mainland China, resulting in higher prices for their lighting fixtures. As for how to determine which type of LED chip is used, only the manufacturer can truthfully inform or observe or test its LED tubes.