Announced on July 19, 2004, the 4th generation iPod replaced the touch wheel from the third generation iPod with the Click Wheel from the iPod Mini, putting the four auxiliary buttons underneath a touch-sensitive scroll wheel. The casing was also slightly slimmer. Pricing was reduced and the lineup was simplified, as the 20 GB model was sold for US$299 and the 40 GB model for US$399. Notably, Apple began reducing pack-in accessories starting with the 4th generation. While a dock, carrying case, and wired remote were previously included with higher-end iPods, the higher-level 40 GB iPod only came with a dock, earphones and an interchangeable proprietary cable capable of USB and FireWire interface. In addition to using the iPod Mini's Click Wheel, the fourth generation iPod used the more energy-efficient components of the Mini, allowing the 4th generation iPod to over 12 hours of battery life while using the same battery as its predecessor.