I recently read from some guys on reddit that when they got one of the cheap keychain laser pointers with tips, one of the tip was a naked lady.
I think many people here owned one of these lasers. Did you also got that tip?
Its the plus-minus sign. It simply indicates that the wavelenght is not exactly like it says but pretty much the same. Its like the tolerance of error (a range within which the error is considered acceptable)
I can easily edit them if anyone wants a certain wavelengh, power-output and laser class. Then you can download them and print them on sticky paper in passport photo size