Combined sensor forms develop finish protection. Merge optical smoke alarms for dwelling areas with heat alarms for kitchens, all linked through radio signals for unified fire detection. Most radio-interlinked alarms have A selection of one hundred fifty meters in an open Place and as much as 50 meters in structures. https://www.thesafetycentre.co.uk/blog/ems-wireless-firecell-systems-from-the-safety-centre/