This Chip on Board COB Led Light is very small and innovative product, it comes in many different Shapes and Sizes. Its mostly used where the thickness of the product is very important consideration. These led comes with aluminum metal back which act as heat dissipating area for the Led,as these led got hot while running. Input Voltage:- 3V- 3.7v Max Input Voltage:- 4v (More than 4v Voltage will completely damage the product ) Aluminum Back as a heat sink. Double Ring Led Light.