Bundle Includes 10 Smoke Alarm E10 + 5  Indoor Siren E20 Expansive Wireless Range with a US version of HomeBase™: Provides a stable connection with HomeBase™ at open-air distances of up to 656 ft (200 m). Requires a US version of HomeBase™ to Operate:  Compatible with HomeBase ™ Mini (v4.0.5.2 or above), HomeBase ™ 2 (v3.4.1.2 or above, released after 2021), HomeBase ™ 3 (v3.7.2.6 or above), and HomeBase ™ Pro (v4.1.4.3 or above). Ensure your HomeBase ™ is updated to the latest version for optimal performance.  Smoke Alarm E10:  Accurate Fire Alerts: Complies with UL 217 10th edition standards, ensuring precise detection of various smoke types without triggering false alarms. Ultra-Compact Modern Design: With a diameter of just 70 mm (2.75 in), this smoke detector is one-third the size of traditional models, blending seamlessly into any home environment. Long-Lasting 5-Year Battery Life: A high-quality CR123A battery and low-power technology ensure long-lasting performance with minimal maintenance and fewer battery replacements. eufy Indoor Siren E20: Loud 110 dB Alarm for Whole-Floor Coverage: Powerful enough to alert the entire floor, ensuring a timely response. Reliable Power with Backup Battery: The rechargeable battery provides 48 hours of backup during power outages and automatically recharges when power is restored. Flexible Installation Options: Place on a desk, attach to a wall using the included 3M adhesive strip, or mount with screws.