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Replacement for BRK 760MBX & 770MBX Mains Powered Smoke Alarms

Discontinued Product

The manufacturer has withdrawn from the European market and is no longer supplying compatible alternatives. Since it is not possible to interlink alarms from different manufacturers, the recommended replacement for the whole discontinued BRK 700MBX range is the Kidde Firex series.

alternative product

Kidde Firex Mains Powered Alarms with Alkaline Battery

  • 230V mains powered with alkaline back-up battery
  • Available in Ionisation, Optical and Heat versions
  • Interlink with up to 24 units
  • Suitable for BS 5839-6: 2019 Grade D2 installations
  • Kitemarked and CE marked
  • Please note: alarms are sold individually
  • Also suitable for the 2022 Scottish legislation

£17.75 inc VAT

£14.79 ex VAT

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Product Overview

The BRK 760MBX and 770MBX smoke alarms with push-fit base are no longer available for sale. The BRK 600MBX series of alarms are identical in every way to the 700MBX series – the only difference is that the spare base supplied is a twist-fit version rather than the push-fit you already have installed. This replacement detector head fits directly onto your existing push-fit base and is guaranteed to be compatible with your existing system.

This BRK 660MBX is a mains powered optical smoke alarms which uses a replaceable 9V alkaline battery as backup. Optical smoke detectors such as the 660MBX are largely replacing the older ionisation smoke detection technology and are better at detecting slow, smouldering fires. This makes them ideal for most rooms in the house such as hallways, living rooms, bedrooms, and landings, including rooms that are usually covered by traditional ionisation alarms. The 760 and 770 alarms use the same base so your new alarm is guaranteed to fit and be compatible with your existing system.

  • Genuine BRK-made replacement for 760MBX and 770MBX alarm heads
  • 230V mains powered with 9V alkaline back-up battery (included)
  • Optical sensor for more accurate detection and reduction in false activations
  • CE and Kitemarked to BS EN 14604: 2005
  • Fits onto your existing BRK push-fit alarm base
    • Twist-fit base included to keep as a spare
  • Interlink with up to 12 compatible alarms in your current system
  • Combined Test & Hush button feature
  • Manuacturer's 5 Year Warranty
  • Product warranty and life commences from date of purchase

The simple installation process of the 660MBX replacement alarm negates the need for an electrician, though you must ensure that mains power to all interlinked alarms is turned off before beginning work. The interlink wire can carry a live electric current between alarms if they are powered from different circuits.

Technical Data
Product Code BK76RA
Alternative Product Codes BK760MBX, 760MBX, BK770MBX, 770MBX, BK660MBX, 660MBX, BRKEOA
Brand BRK
Back-Up Battery

Replaceable 9V Alkaline

Dimensions (HxDia)

44 x 140mm (including base)

Operating Temperature

+5 °C to +38 °C

Relative Humidity

10% to 85%

Sound Output


Weight 0.27kg
Product Datasheets

Key Product Features

Perfectly replaces both the 760MBX optical and 770MBX ionisation smoke alarms

Alarm head fits directly onto your existing base - no electrician needed

The supplied 9V alkaline battery can be easily replaced

Made by the original alarm manufacturer BRK

What's Included?

Every BRK BK76RA is supplied with the following components.

  • 1 x BRK 660MBX optical alarm
  • 1 x Spare twist-fit base
  • 1 x 9V replaceable alkaline battery
  • 1 x Screw fixing set (screws & rawl plugs)
  • 1 x Instruction manual

Excellent Warranty

This product is supplied with a 5 year manufacturers warranty as standard

Looking for more information?

If you have any questions or would like more information about this product you can ask one of our specialists.

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