IBM ThinkPad Laptop AC Adapter - 72W, 02K6657 02K6669 16Volt, 4.5Amp T20-T21-T22-T23-T30-T40-T41-T42-R30-R31-R32-R40 IBM ThinkPad See description for aternate Part Numbers that this can be substituted for. See description for all of the laptops that this can be used with. Specifications: 16V 4.5A