The U series by Toshiba is now less known and consists of the Toshiba Satellite Pro U300 which fits the 19v 3.95a laptop charger which happens to also fit the range of Toshiba Satellite Pro U400 also. The Tosh Sat Pro U500 charger will work fine with the U300 and U400 power adapter but recommend and supplied with new is the 19v 3.42a version.  So click your model below or click the model series for your genuine AC adapter.