The main material--solid Oxygen bgranule is high science and technology product of biology Which is developped recently.All kinds of colors solide granule matter.It has been immerged water for four days,which has sended out Oxygen slowly.It contains abundant nourishment which can purify water,specially be used aquarium,all kinds of inclosed fishing-farming .If put it in the aquarium glass of bedroom or workroom,it has make people get fresh air.