1High Accuracy: This LED constant current driver board consists of high accuracy reference voltage, amplifier, current mirror and so on. 21MHz Switching Frequency: This LED constant current driver board adopts 1MHz switching frequency, which is very sensitive. 3High Efficiency: This LED constant current driver board has high efficiency up to 96%, which is perfect for LED drivers which is very practical. 4Multifunctional: This LED constant current driver board is multifunctional with high side current detection and over temperature current drop function. 5Knob Design: This LED constant current driver board comes with a knob switch, which is very easy and convenient to use and adjust. 1 x LED Constant Current Driver Board ( With Twisted Cap, Nut, Spacer)