Microvilli

 Microvilli are tiny hairlike protrusions that extend from the apical surface of some epithelial cells and many other cells involved in absorption and secretion. They are only tiny structures, at about 0.08µm in width but due to their vast number they greatly increase surface area for absorption and secretion in cells. 

Each Microvillus stems from one much larger villus, another hair like protrusion, these are between 0.5 and 1.6mm in length.