OtterBox has expanded its line of Pink Strength cases with a special release of its Defender Series case for the fourth-generation iPod nano. As with past Strength cases, 10% of the purchase price of the Defender nano 4G will be donated to the Avon Breast Cancer Crusade to support access to care and finding a cure for breast cancer. The case features a unique three-layer design consisting of a thin clear membrane to protect the screen and Click Wheel, a hi-impact Polycarbonate skeleton, and an outer layer of silicone to provide added bump and shock protection. It also offers access to the Dock Connector, hold switch, and headphone jack via silicone plugs, and has a built-in stand for watching movies and videos. The OtterBox Defender Strength case for the iPod nano 4G is available now and sells for $30.