Selling my Lenovo Active Pen, purchased just eight months ago, but only used once – it's practically brand new! Still in it's original packaging. - Compatible with: Yoga 900S-12ISK, Miix 700-12ISK, Miix 510-12IKB, Miix 510-12ISK, Miix 720-12IKB - 2048 Levels of pressure sensitivity - Palm Rejection. Powered by a single AAAA battery, the Lenovo Active Pen also features two built-in side buttons for ease-of-access to applications. A USB pen holder for storage and three replacement pen tips for longer use Streamlined metal body design. - Operating Systems: OS Independent. Batteries 1 AAAA batteries required. (included)