A Chinese brand, Kingdunalarm, made LM-101LG for years, in EU, they have been imported since at least 2013, and are often marketed under the name No-Flame, Nor-Tec and others. This is a reliable, linked optical smoke and heat detector.
This modification adds Zigbee compatibility, so that you can receive a notification whenever the alarm is sounding (triggered by test button forwarded from another linked alarm, or if the device itself sounds the alarm.)
For this modification, I am using a Tuya ZG-102ZL Door/window hall-effect sensor.
https://www.zigbee2mqtt.io/devices/ZG-102ZL.html
This is the modified ZG-102ZL:
The Hall-effect sensor was where the white wire goes, (you need to remove the device)
Blue wire is ground, red will get 3.3v from the smoke detector, white wire gets the signal.
This is the smoke detector’s PCB:
Red wire goes to Tp11.
White to Tp12.
Blue to ground.
A suitable spot for the Zigbee device: (I’ve desoldered it’s battery holder.)
Customised view in Home Assistant:
