i already have a few, want more to make a rapid fire laser, since they have limited duty cycle each, i could fire one after the other sequentially to give each one a rest. i keep getting these units which have problems, missing a flash lamp, destroyed q-switch for not putting an inductor in line with the flash lamp, someone sawed off a mounting leg on one of the frames, those kinds of issues. i get them cheap when they have problems (normally, not the last one) so I don't mind to buy more to make complete units.