The optics of STL H GROWLIGHT are a LUXLED project, they are used to concentrate and direct the light only where it is needed, without dispersion; our optics are one of the factors of the very high efficiency of our projectors. In addition to this, the optics also act as gaskets giving the STL front, together with the aluminum screen, a perfect watertight seal. In fact, the front protection of the STL H is IP69K!