A curable silicone rubber composition is described for an LED enclosure or packaging. A process for preparing the same and the use thereof are also described. Particularly, the compositions can include at least one tackifier component D, which includes: a) a alkenyl or hydrosilyl group including an isocyanurate compound E, and b) an adhesion-imparting ingredient having at least two functional groups selected from the group consisting of alkenyl, epoxy, alkoxy and hydrosilyl groups, which includes of polysiloxane F and optional coupling agents G.