It can dissipate heat away from the bottom of the notebook and cool down the overall temperature of the system. More ergonomic typing angle design, eliminate your neck and wrist's ache, use it often is good for our health. Its features as follows: 2 or 3 built-in cooling fans dissipate heat away from the bottom of the notebook & cool down the overall temperature of the system USB-powered for use with any computer USB port Heavy-duty construction withstands constant pressure of heavy notebooks Compact size offers easier portability while traveling Human engineering guide design, comfortable for eyes and backbone Environment protected Acrylic material with the feature of high rigidity Overall size: 290 x 240 x 46 mm Fan size: 70 x 70 x 15 mm Reated voltage: 5 VDC Fan Speed: 1500+10% RPM Noise Level: < 19 dBA Material: Acrylic Acrylic resembles glass but is many times stronger than glass, more impact resistant and therefore safer. Acrylic offers exceptional optical properties, Crystal clear, like Crystal, enjoying the reputation of "queen of plastic", uniform thickness and low stress level, superior weather resistance and half the weight of glass.