The L-173GD is a Kingbright 5.0mm green LED, which is a high-efficiency light-emitting diode, designed for use in a wide range of applications. It has an elliptical plastic lens, with a numerical aperture of 17 degrees, and a view angle of 40 degrees. It requires an operating voltage of 2.1-2.4V and an operating current of 20mA and a power dissipation of 40mW. It is RoHS compliant, making it a reliable and safe choice for a variety of projects.