This is an installation manual for the Panasonic KX-TGA401 Digital Cordless Headset. The headset is compatible with the following series of Panasonic digital cordless telephones: KX-TG4011, KX-TG4021, KX-TG4031, KX-TG4051, KX-TG4071, KX-TG6511, KX-TG6521, KX-TG6531, KX-TG6541, and KX-TG7531.