Nogis Round 5.5*2.1mm Power Charger Tip Adapter Connector Converter For Lenovo Ideapad Yoga 11, 11s, 13, 2 Pro, Flex 14, 15 ; Lenovo ThinkPad T440S T450S Yoga Helix, x240, Carbon X1 T540P ,P/n 0b46994, 0c19868, 0b47046, 0b47048 Ultrabook From Old Universal Charging Cable Cord (Round Connector) To New Updated Lenovo Square Connector On Power Adapter Compatible with :Lenovo Ideapad Yoga 11, 11s, 13, 2 Pro, Flex 14, 15 ; Lenovo ThinkPad Helix, x240, Carbon X1 ; Compatible P/n 0b46994, 0c19868, 0b47046, 0b47048 Ultrabook Laptop Convert Round to Square Connector For your New Updated Lenovo Laptop.Connect your old charger adapter (round connector ) to your new Lenovo laptop (square connector),no need buy a new power supply about (40 USD). Saving your MONEY! Perfect for charging laptop with portable battery pack,make your laptop life to 8+ hours . Tip Diameter :5.5*2.1mm,Be careful about the tip size ,make sure the size fit your needs before purchasing. PLUS, it has a USB connection can charge your iPhone when use laptop.