![Kidde Fyrnetics KF20 Firex White Mains Optical Smoke Alarm With Hush, Mounting Plate & Alkaline Battery Back-Up 230V - Shop4 Electrical Kidde Fyrnetics KF20 Firex White Mains Optical Smoke Alarm With Hush, Mounting Plate & Alkaline Battery Back-Up 230V - Shop4 Electrical](https://shop4electrical.co.uk/665967-medium_default/kidde-fyrnetics-kf20-firex-white-mains-optical-smoke-alarm-with-hush-mounting-plate-alkaline-battery-back-up-230v.jpg)
Kidde Fyrnetics KF20 Firex White Mains Optical Smoke Alarm With Hush, Mounting Plate & Alkaline Battery Back-Up 230V - Shop4 Electrical
![New Kidde FireX KF20 Mains Powered Optical Smoke Alarm Fire Detector with 9V Battery Backup : Amazon.co.uk: DIY & Tools New Kidde FireX KF20 Mains Powered Optical Smoke Alarm Fire Detector with 9V Battery Backup : Amazon.co.uk: DIY & Tools](https://m.media-amazon.com/images/I/71iRBt2Xn2L._AC_UF894,1000_QL80_.jpg)
New Kidde FireX KF20 Mains Powered Optical Smoke Alarm Fire Detector with 9V Battery Backup : Amazon.co.uk: DIY & Tools
![Hi, I'm going to attempt to replace these Firex smoke detectors myself. can I just buy the most recent model of these and swap them out, leaving all the old wires? Or Hi, I'm going to attempt to replace these Firex smoke detectors myself. can I just buy the most recent model of these and swap them out, leaving all the old wires? Or](https://i.redd.it/7nce6mtqp4ba1.jpg)
Hi, I'm going to attempt to replace these Firex smoke detectors myself. can I just buy the most recent model of these and swap them out, leaving all the old wires? Or
![Kidde Part # 21029877 - Kidde Firex Smoke Detector, Hardwired With Battery Backup & Front-Load Battery Door, Smoke Alarm - Smoke Detectors - Home Depot Pro Kidde Part # 21029877 - Kidde Firex Smoke Detector, Hardwired With Battery Backup & Front-Load Battery Door, Smoke Alarm - Smoke Detectors - Home Depot Pro](https://content.interlinebrands.com/product/Image/Detail/10271/604005_usn.jpg)
Kidde Part # 21029877 - Kidde Firex Smoke Detector, Hardwired With Battery Backup & Front-Load Battery Door, Smoke Alarm - Smoke Detectors - Home Depot Pro
![Kidde Firex KF20 Optical Smoke Alarm - Mains Operated with Battery Back Up : Amazon.co.uk: DIY & Tools Kidde Firex KF20 Optical Smoke Alarm - Mains Operated with Battery Back Up : Amazon.co.uk: DIY & Tools](https://m.media-amazon.com/images/I/31FEUB5lwSL.jpg)