Lenovo that tracks the progress of these integrations. Lenovo has an annual meeting where the management of newly acquired companies meets with its top 100 executives. In these meetings, held in English, Lenovo explains its global strategy and how new executives fit into its plans. Lenovo acquired IBM's personal computer business in 2005, including the ThinkPad laptop and tablet lines. Lenovo's acquisition of IBM's personal computer division accelerated access to foreign markets while improving both Lenovo's branding and technology. Lenovo paid US$1.25 billion for IBM's computer business and assumed an additional US$500 million of IBM's debt. This acquisition made Lenovo the
ThinkPad millionth unit of its ThinkPad line. Some Lenovo laptops (such as the X230, W530 and T430) block third-party batteries. Lenovo calls this feature "Battery Safeguard." It was first introduced on some models in May 2012. Laptops with this feature scan for security chips that only ThinkPad-branded batteries contain. Affected Thinkpads flash a message stating "Genuine Lenovo Battery Not Attached" when third-party batteries are used. The ThinkPad Yoga is an Ultrabook-class convertible device that functions as both a laptop and tablet computer. The Yoga gets its name from the consumer-oriented IdeaPad Yoga line of computers with the same form factor. The