Patent no. : ZL 2011 1, 0049789.6, equipped with 1 to 4 sets of laser, can work at the same time, work, work alone or alternate each other. A similar form on multiple engines, to guarantee the strong laser energy output. Have a spare laser, uninterrupted operation, ensure the continuity of the operation and safety. Single pulse energy is 5.0 J, the output frequency 50 hz, shorter operation time, better treatment effect.