This sticker sheet features 27 (!!!!!!) different species of freshwater algae. From diatoms to blue-green algae, both macro and micro, these babies have it all. A niche gift for the aquatic ecologists/ phycologists/ limnologists and great for any museum, scientifically-oriented, or nature loving gift shops. Waterproof, weatherproof thick vinyl sticker. 4x6 inch sheet.