Alecto SA-230 is an optical smoke alarm device that detects smoke and sets off an 85dB alarm. It is battery operated and has a test button to ensure it is working correctly. The SA-230 is suitable for use in all living areas, including bedrooms, hallways, and living rooms. It is not suitable for use in kitchens or bathrooms, as steam and cooking fumes can trigger false alarms. The SA-230 has a low battery indicator that will sound when the battery needs to be replaced.