The ThinkPad 4X20E50561 135W AC Adapter (slim tip) is an efficient and powerful power adapter for Lenovo Thinkpad laptops. The device has a power output of 135 watts which means fast charging is guaranteed. The connection to the laptop is simple because of the slim tip design. The Adapter has safety measures against overheating and overcharging built within the device. In summary, the 4X20E50561 Lenovo ThinkPad 135W AC Adapter powers Lenovo ThinkPad laptops and is reliable and high-performing.