Compatible with :
Lenovo ThinkPad X1 Carbon  AC Power Adapter / Charger

Specifications:
Input Voltage : 100V-240V 
Output Voltage : 20V
Output Power : 4.5A, 90W
DC Tip Size : Rectangle USB Type with Yellow Tip with Pin Inside
Over voltage protection
Over temperature protection
Short-circuit protection

Package included :
1 x Lenovo AC Power Adapter/Charger 
1 x Power Cable  Type : UK 3-PIN with Fused