The two generations of iPod Mini were almost identical in their external features, except for two noticeable differences: the first generation model has gray control symbols on the click wheel, while those on the second generation matched the color of the body, and the player's storage capacity was etched on the back of the second generation body. Their major functional differences lay in their storage capacity and battery life. Both versions were 3.6x2.0x0.5 inches (91x51x13 mm) and weigh 3.6 ounces (102 grams). The case consists of anodized aluminium. First generation iPod Minis were available in five colors: silver, gold, pink, blue, and green. The gold model was dropped from the second generation range, likely due to its unpopularity. The pink, blue, and green models had brighter hues in the second generation; the silver model remained unchanged.