This is a high efficiency lens for 405 to 520nm "aixiz"-style laser modules. Compared to standard aixiz glass or acrylic lenses it will increase the laser output by 15-30% depending on wavelength (color). If you want more power from your laser, this is likely your best shot.
This lens fits all our green, blue and violet lasers, but some of them already use this lens, make sure the laser you want to upgrade does not or you will see no improvements. The lens used is stated in the specifications on the product information page of the laser.
NB: This lens may create a "dirtier" dot with more side splash an distortion, that is a side effect of letting more light through the lens.