The SB1 optical standalone smoke alarm is ideal for grade F2 installations where cost is a priority and basic fire protection is required. Optical alarms are recommended in the British Standard BS 5839‑6 for installation in circulation areas such as hallways and landings. 1 year replaceable battery 10 year product life For use in hallway, landing, living room, dining room and bedroom Optical sensor as recommended by BS 5839-6 BS EN 14604:2005+AC:2008 Grade F2 – Suitable for low-cost budget installations requiring basic fire protection Easy installation – A quick and easy solution that provides instant protection with no interlinking required