Soewolit’s combination alarm puts two essential safety monitors into one ceiling plate. The digital display is the clear advantage here, giving you a real-time readout of carbon monoxide levels. You don’t have to wonder what triggered the alarm; a glance tells you if it’s a low-level CO presence or an emergency.

It uses separate photoelectric and electrochemical sensors for smoke and CO, which is the proper way to build a combo unit. The photoelectric sensor is better at spotting slow-burning, smoldering fires. The over-80dB alarm is jarringly loud, as it should be. A low battery chirp reminds you to swap the included battery, likely every year.

Installation is straightforward, but remember this is a battery-only device. You won’t get interconnected alerts to other units in a larger home. For a single room or small apartment, it delivers critical information at a glance.