Question about FD25 - 402429

A shorter "Ding Dong, Ding Dong" and a slightly higher tone. There is also a mute indicator. The rest are mostly dumb tones. You can change the volume and save different detectors with different sounds or modes. I.e. detector A makes a dingdong, detector B crows like a rooster, etc. This way you know where someone is. I have three devices in use in the back office and in the warehouse and they reliably report whether someone is in shop area A or area B. The devices have been working perfectly for years. It has worked perfectly for years. Several transmitters and receivers can be linked, and the detector goes berserk when the batteries in the transmitter are ready to be changed. So I can only recommend it.