Complex sentence: The iPod Mini uses the touch-sensitive scroll wheel of the third generation iPod; however, instead of the four touch buttons located above the wheel, the buttons were redesigned as mechanical switches beneath the wheel itself--hence the name "click wheel".
Split into simpler sentences: The iPod Mini uses the touch-sensitive scroll wheel of the third generation iPod. However, instead of the four touch buttons located above the wheel, the buttons were redesigned as mechanical switches beneath the wheel itself--hence the name "click wheel".