Patent ID: 7519176

Claim:
A key telephone set comprising: a telephone main body comprising a handset placing unit; an interchangeable dial button unit attached to said telephone main body; an interchangeable line button unit attached to said telephone main body; and an interchangeable display unit attached to said telephone main body, wherein said telephone main body, said interchangeable dial button unit, said interchangeable line button unit and said interchangeable display unit are structured so that said interchangeable dial button unit, said interchangeable line button unit and said interchangeable display unit are detachable from said telephone main body without disassembly of said telephone main body, wherein said interchangeable line button unit is attached to said telephone main body with a first sliding attachment mechanism, wherein said interchangeable display unit is attached to said interchangeable line button unit with a second sliding attachment mechanism and thereby said interchangeable display unit is attached to said telephone main body through said interchangeable line button unit.