INTERSTATE TEL0040 3.6V 300MAH CORDLESS TELEPHONE REPLACEMENT BATTERY. Fits: Aastra Telecom 4525 MAESTRO, 4600 MAESTRO, 4625 MAESTRO, AT&T 1145, 1165, 1177, 1187, 1445, 1465, 1477, 1487, 22030X, 22031X, 22032X, 22036X, 22038X, 22040X, 22041X, 22042X, 22072X, 22074X, 22143X, 22145X, 22183X, 22184X, 22196X, 22200X, 22204X, 22208X, 22212X, 22213X, 2230, 2255, 2422, 3000, 3050, 3400, 3410, 400, 4000A, 4000X, 4051, 4061, 4110, 4200, 4210, 4225, 4300, 4305, 4310, 4315, 4320, 4325, 4330, 4331, 4335, 4336, 4337, 4340, 4345, 4400, 4410, 4500, 4571, 4600, 4605, 4610, 4615, 4690, 4695, 4725, 4800, 4805, 4810, 4815, 5000, 5030, 5200, 5210, 5250, 5300, 5310, 5320, 5352, 5400, 5405, 5420, 5450, 5455, 5460, 5470, 5471, 5475, 5480, 5481, 5483, 5484, 5489, 5490, 5491 3.6 Volts 300mAh