Model ST-ABS3-R is a Loop Isolator, which is fully compatible with Hochiki's ESP analogue addressable protocol. The ST-ABS3-RBase has been designed to be is compatible with any of the ESP wall sounders, the ST-AWS-W wall sounder and the ST-AWSF-RWL wall sounder beacon. The Base incorporates an amber LED to show when it is isolating a section of the loop. The ST-ABS3-R does not use an address, and has the same wiring configuration as the ST-ABI-W Sensor Base making it very simple to install. The ST-ABS3-R can also be used without a sounder; a cover can be fitted to conceal the wiring connections.