This is the flush mount version of the FG1625 from Honeywell that utilizes the Flex-Core processing that can distinguish between real breaking glass and false alarms with this new innovative technology. This unit is easy to setup and install and can be remotely tested with a simulator. It has two DIP switches internally that you can use to set the sensitivity to match the acoustics in the room that you install it in. There is no minimum range and the max range is twenty five feet. It can detect breaks on all kinds of glass.