The JST25A06-BW is a two-way thyristor made by Haoruijia, with a 600V TO-220A RoHS rating. It is a TRIAC (Triode for Alternating Current), which is a semiconductor device that enables the flow of current in either direction and can be triggered by a low-voltage, low-power signal. It has a maximum current rating of 25A and can be used in a wide variety of applications such as motors, lighting systems, home appliances, and more. It is suitable for both AC and DC applications, and is RoHS compliant, ensuring it is safe for use in the majority of modern products.