HAROS Excimer lasers are xenon chloride (XeCl) lasers that deliver concentrated, high-dose monochromatic 308nm UVB phototherapy directly to psoriatic and depigmented lesions limiting exposure to surrounding healthy tissue.  Unlike conventional UVB systems that emit wavelengths from 290 to 320nm, PHAROS excimer lasers deliver only monochromatic 308nm, an efficacious wavelength for treating psoriasis, vitiligo, atopic dermatitis, and leukoderma. Continuously adjustable with constant fluence, PHAROS' infinitely variable spot size handpiece and aiming beam allow targeted treatment of affected tissue quickly, easily, and accurately while limiting exposure to healthy skin. 

It also means that psoriasis patients may need fewer treatments than with traditional phototherapy. 

Moreover, while each patient is unique, psoriasis patients may enjoy several months of treatment-free remission.

For vitiligo patients, repigmentation may begin after as few as 6 sessions.  While the degree and speed of repigmentation is greatly effected by the anatomical location of the disease, some treatment regimens consist of 15 to 30 sessions on a twice weekly schedule. 

For both psoriasis and vitiligo patients, these positive patient outcomes encourage patient compliance and enhance satisfaction.

The PHAROS EX-308's unique lightweight handpiece features an integrated adjustable spot size and corresponding brightly-lit aiming beam. By gently sliding the finger-switch on the handpiece, the laser beam is easily contoured to match the size of the lesion for fast targeted treatments.

Source: http://www.ramed.com/ramedical_products.html