Features:
Taillight controller can convert your front or rear turn signals standard ing action to successive lighting.
The 3-step sequential chase module boxes are universal fits for most cars.

Supports up to 21 W simultaneously?
The "simultaneously" means the 3-step sequential module box can support up to (3) 21W bulbs at one time. This is because not all three light bulbs at the same time.

Use?
The pair of sequential module boxes are fit for many cars but ting actions are required in order to install it. To install the 3-step dynamic module boxes, modifications such as wiring and wire extending are required.

How to connect the wire?

All three light applications' black wires must be tapped to the module box's single black wire which is what we call the common ground/negative wire.

If the car uses the same light bulbs on rear turn signal and brake lights. Will I can use this box set for my turn signals alone?
No, if your turn signals and brake lights share the same bulbs the dynamic ing module boxes will not be able to make your turn signal lamps alone sequentially.

Specification:
Color: Black
Material: ABS, PC
Voltage: DC 12V
Fit Type: Universal
Item Type: Tail Light Controller Module
Dimension: 6.4x3.6x2.1cm / 2.51"x1.42"x0.82"(L*W*H)

Installation Steps:
Needed some ting work
Needed professional installing
If no need the output adapter, you could cut it off.

Package Include:
2 x 3-Step Dynamic Sequential Module