It appears that the LaserComb is not FDA approved for hair growth and it has not been proven to work with peer-reviewed research.  Does it work?  Maybe, I think the jury is still out.  However, I would take the FDA approval marketing scheme with a grain of salt.  Be aware that the approval is based on safety, not necessarily effectiveness.  
The Hairmax LaserComb is a product that is developed by Lexington International, LLC. 
Here is a brief summary about what the LaserComb can be used for, and if it really works.   The HairMax LaserComb is a Laser Photo Therapy (LPT), medical device to treat androgenetic alopecia in males.
Ok, so what is LPT?  According to Wikipedia,
“devices are sold that use a low level laser shone directly on the scalp with the intent to stimulate hair growth through “Photo-Biostimulation” of the hair follicles. One product of these low level laser therapies is the Hairmax Lasercomb. There is some debate over the FDA’s acknowledgment of the Lasercomb.[24] Under the looser standards applicable to medical devices, the HairMax LaserComb was cleared by the FDA as being “substantially equivalent” to predicate devices legally marketed before May 28, 1978. The devices that the lasercomb proved itself equivalent to were a variety of FDA approved non hair growth/laser based devices intended for hair removal and pain relief, and two non FDA approved non laser based/hair growth devices such as the Raydo & Wonder Brush and the Vacuum Cap. These last two devices were sold in the early 1900s and are well established as medical quackery, but they were legal to market at the time which does satisfy the FDA’s minimal 510k SE criteria. The 510k number for the Lasercomb is K060305.”
None of these claims have been substantiated by peer-reviewed evidence.
So what is androgenetic alopecia?  This is male-pattern baldness. Hair is lost in a well-defined pattern, beginning above both temples. Over time, the hairline recedes to form a characteristic “M” shape. Hair also thins at the crown of the head, often progressing to partial or complete baldness.
Here is the bottom line on what exactly the LaserComb is.  It is a device that is FDA approved as “substantially equivilant” to devices that were not intended for hair growth.  Additionally, it is intended for males suffering from male-pattern baldness and not any other type of hair loss issues.

It appears that the device is not FDA approved for hair growth and it has not been proven to work with peer-reviewed research.  Does it work?  Maybe, I think the jury is still out.  However, I would take the FDA approval marketing scheme with a grain of salt.  Be aware that the approval is based on safety, not necessarily effectiveness.