The Solatube Smart LED is a Solatube with the addition of LEDs to enable you to light a space at night. There are twop options: primary LED or primary LED w/ secondary system (another set of LEDs) depending on how much light is required. A Daylight Sensor continually monitors light levels within the tube and activates the LEDs when light levels reach a minimum threshold. It also deactivates the LEDs when sufficient daylight is present. There's even an option for a daylight dimmer in case it's too bright during the day!
The LEDs are 35 lumens/watt, which is considerably lower than traditional screw-in LED bulbs, so if there is already an LED light source as an option, you may want to consider this and just stick with the standard Solatube.