The UVB-5X173 is 12.7mmx6.35 rectangular light bar. Choices of three bright colors-high efficiency red/green/yellow. The high efficiency red devices have red bars,green devices have green bars,and yellow devices have yellow bars. The high efficiency red and yellow LED chips are made from GaAsP on a transparent GaP substrate. The green LED chips are made from GaP on a transparent GaP substrate.