NSON makes a genuine laser.
The medium of Alexandrite & Nd;YAG are governed by the weight of ROD. In particular, Rod of Alexanderite is one of a high-priced parts and its weight determines the quality of energy. (The Alexander ROD weighs about 31g and the Nd :YAG ROD weighs about 38g.)
PENTO 9900 adopts rod direct resonance method instead of optical resonance method to use High Power