There has never been elevator telephone with the function----several group number sequence dial in China before. In a case of emergency in elevator, the passengers call for help through the elevator telephone. And if the elevator telephone stored only one group number is busy, it will delay the best rescuing time. Now, KOON have created the industrial and Military elevator telephone with the function---storing several group number. And those telephones has high anti-interference capability, reaching to the international standard EN50121.
A set of telephone can store the number of guard's room and store the number of shift supervisor and project leader at the same time. When the first number is busy, the telephone will automatically switch to a second number and it can suspend the primary call. And it can be made into wireless elevator telephone with anti-interference capability reaching to the international standard EN50121.