Get power when and where you need it, with the ThinkPad 135 W AC adapter. Keep one in the office, one at home and another in your carrying case for convenient access to power. Just plug it into an available wall socket to deliver AC power to your compatible ThinkPad laptop and recharge the system battery. ThinkPad AC adapters are compact, energy-efficient (Energy Star V (ES 2.0) rating) and backed by a one-year warranty Performs to the same specifications as the standard AC adapter that is supplied with ThinkPad laptops, so it is a perfect replacement or spare. The ThinkPad 135 W AC adapter is only compatible with ThinkPad laptops with a rectangular ?slim tip? common power plug. It is not compatible with ThinkPad laptops with the round, barrel-type power plug.