this invention provides a novel class of organohydrogenpolysiloxanes that function as curing agents for organosiloxane compositions curable by a hydrosilylation reaction in addition to imparting excellent adhesion to the cured composition . this invention also provides curable organosiloxane compositions containing these novel organohydrogen - polysiloxanes . the compositions exhibit excellent adhesion to a variety of organic and inorganic substrates , including but not limited to metals , glasses , and plastics .