Features: Suitable for USB powered desk fan,USB ceiling fan, USB LED lamps and more USB powered devices. USB switches extension cable with speed regulation function and brightness adjustment function. With its upgraded design, this cable features a power switches that prevents USB ports from getting worn out. Strong material ensures strength and durability for long lasting usage. Switches with knob. Brightness can be adjusted arbitrarily. Suitable for 5V LED light bar. Specifications: Material:Plastic Length:Approx.16cm/6.2inches Note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1x LED Knob Dimmer