The GL4520F is a Photoresistor through-hole detector made by Jing Chuang. It is RoHS compliant, meaning it is designed to meet environmental regulations regarding hazardous substances. It is a type of electronic component used to detect light. It converts light energy to electrical energy, and its resistance varies in proportion to the light intensity it receives. This makes it useful in applications where light needs to be detected, such as in outdoor lighting systems or in security systems. Its features include a high sensitivity range, a curved-shaped sensitive area, and an integrated housing. It is also designed with anti-thunderbolt capability, which makes it highly reliable in especially harsh environments.