Based on this product's specifications, here are some alternatives and similar models
Rate-of-rise heat detector Olympia 6120
Summary description:
The Olympia 6120 is a wired interconnectable surface-mounted rate-of-rise heat detector. It operates on a 1.5V AAA battery and features a compact design with dimensions of 70mm width, 65mm depth, and 25mm height. This reliable detector is ideal for early fire detection, ensuring safety in residential and commercial spaces.