I am looking for a wireless door chime. I want something that I can carry anywhere in the building with me that will ring whenever the shop door is opened. I tried the using a Claron wireless door bell chime with a door sensor which both claim to have a 150 foot range and it only works within 30 feet of the door. My building is 100 feet long and I want something that will work anywhere in the building.
Does anyone have a wireless door chime that they are happy with that they would recommend so I don't continue to buy things that don't fit my needs?