Made for a greener planet, the Top Solar Calculator, designed by Seiichi Fujimoto is equipped with a solar battery that is charged by a strong light source. But to ensure that it also functions under unfavorable light conditions, the Top Solar Calculator also uses an LR44 Button battery as backup. This contemporary calculator with its 12-digit display was a Good Design Award 2007 winner (Ministry of International Trade and Industry, Japan). Made of ABS plastic. Dimensions: 4" x 4" x .5"