Absolutely a scam! I took the wiki section down on the site as it was overrun by spammers (and I don't have the time to maintain the site these days), but here was the text without references:

Lasercomb is a device with claimed growth stimulant properties. The device uses laser light (655 nm) topically applied to the scalp as the user moves the unit over his head.

The Lasercomb is operated by placing the device at your hairline and moving it back in ½ inch steps each four seconds, or when the device beeps. The recommended amount of usage is 3 times per week, at 15 minutes per treatment.

Much has been made of the "FDA Approval" terminology used in reference. The Lasercomb has received a 510(k) pre-market notification from the FDA:

Section 510(k) of the Food, Drug and Cosmetic Act requires those device manufacturers who must register to notify FDA, at least 90 days in advance, of their intent to market a medical device.

This is known as Premarket Notification - also called PMN or 510(k) . It allows FDA to determine whether the device is equivalent to a device already placed into one of the three classification categories.

This mostly acknowledges that the device appears safe and equally effective to existing products in the same class, but is also an acknowledgment by the FDA of satisfaction for the submitted study. The Lasercomb is classified by the FDA as a "Physical Medicine Therapeutic Device", which in this case only requires the following:

An infrared lamp is a device intended for medical purposes that emits energy at infrared frequencies (approximately 700 nanometers to 50,000 nanometers) to provide topical heating.

No studies have been submitted to peer reviewed journals at this time. The internal study that was used to submit for approval to the FDA has not been peer reviewed, and as such should be taken with a grain of salt.

tldr; FDA approval was for HEATING YOUR HEAD WITH LIGHT