The univeral 2.5 mm jack handsfree headsets fit all Audiovox cell phones, all Motorola phones (except Razr), all LG cell phones, Kyocera/Qualcomm mobile phones, and the following other models: 

Nextel models:  i30, i85, i90, i95

Samsung models:   A310, A530, A600, A610, A620, A650, A660, A670, A680, A690, A700, A710, A760, A790, A890, S300, S307, S200, all Touchpoint models

Panasonic models:  TX310, TX320, GD55, GD87, G50, X70

Sanyo models: 7300, 8300