ThinkPad X series Gigabit LAN introduced on some models, IBM Security Sub System on some models. Specifications: Three years after the release of the X30, upon acquiring the ThinkPad division, Lenovo released the ThinkPad X41 ultraportable laptop and the ThinkPad X41 tablet. The X41 tablet was convertible, with the capacity to function as a tablet PC and an ultraportable laptop. The X32 was introduced in 2005. The numbering system was a bit confusing, as it was actually introduced after the X40, but using the older X3x chassis design. It was also a bit more powerful than the X40 and X41 units, due to
ThinkPad W series are: The Lenovo W541 is essentially a ThinkPad W540 that featured the new-style keyboard but with a re-introduction of the classic ThinkPad trackpad design. The prior ThinkPad trackpad design featured in the W540 was abandoned. Rather than being a successor of any previous W-series model, the Lenovo W550s is a thinner Ultrabook variant of the W series. While a capable Ultrabook, when compared to the W541 and its predecessors, it offers less capability with only dual-core hyper-threaded Intel Broadwell Processors vs. the true quad-core processors of other models and has only two RAM slots. The ThinkPad W series was replaced