The Samurai Mini Smoke Alarms Model SM1 is a set of two white smoke alarms powered by a lithium-ion battery. These units are easy to mount on walls or ceilings and feature advanced photoelectric sensor technology. The alarms produce a piercing 85-decibel sound and have a long battery life of 10 years. Each unit weighs 3 oz. and has a depth and width of 2 inches. The product is manufactured in 2023 and is ideal for home security.