The BTQ-VM4W/VM8W is wall mount Emergency Notification System controller with integrated battery charging unit for secured battery backup and power sharing. All components contain within one heavy-duty metal housing with a lockable cover. The BTQ-VM850 8 monitored speaker zones respectively. The controller is integrated with 500W high efficiency Class-D amplifier built-in and is capable of handling 1000W speaker load per zone and 2000W max. per unit. Each controller can cascade with up to 31 BTQ-SL8 secondary local units via local digi-link and be networkable with up to 64 BTQ-VM850W or BTQ-SG8 secondary global unit via global-net. This will then extend as little as 4 monitored A/B speaker zones to a large networked system of up to 16,384 zones. The BTQ-SL8 is linked to the BTQ-VM850W via STP CAT5/6 cable with shielded RJ45 connector (max. length 10m between units); and the BTQ-SG8 is linked to the controller via STP CAT5/6 cable with shielded RJ45 connector (max. length 100m between units), multi-mode (2 km) and single-mode (20 km) fibre optics or even longer distance upon request.