Make sure that your home is equipped with a BRK Smoke Alarm. It comes with an ionizing sensing chamber to detect small particles that come from a fire. This 120V AC smoke alarm also has a silence feature that quiets nuisance alerts. There are two locking features and it has pins to keep the battery drawer attached to the base. This BRK 9120B is suitable for placing in an RV. The 9120 Series smoke alarms have been designed to install faster perform better and be even smarter than before. These improvements help reduce nuisance alarms and save you time and money.