Review on SITERWELL Photoelectric Battery Operated GS528A by Jacob Richardson

Not sure about battery life but batteries were included. The scope of delivery includes materials for two different mounting options: screws with dowels and metal plates with double-sided adhesive tape for tool-free assembly. I went with screws and anchors for the two I've hung so far. The tests are working and luckily nothing happened that could bring her down. These are "photoelectric" detectors that work better with slowly smoldering flames and complement the ion detectors I already have. A three pack at this price is good value for added protection for my family.