SABRE Motion Sensor Alarm and 3 Door/Window Alarms, White

So my apartment is 700 sq ft. I'm on 1st floor. 1 window in bedroom. 1 back patio sliding door. Front door. My building is fairly secure. Have to be buzzed in and have keys for side entrances. But I wanted simple protection/warning, being a female and not taking security for granted. I sleep much better with the sensors on, along with my trusted piece. They're just peel and stick on, though it came with mounting screws. I used some heavy duty velcro strip for the keypad/front door. If they come unstuck, which it doesn't appear they will, I'll velcro them as well. Make sure they're aligned properly. They're loud enough even if you just need the warning that an entry has been breached. They'll definitely scare off an intruder. The door keypad/sensor is good and super loud. I have 1 leftover sensor and may just stick on window for even more sound. So here's a couple things negative... the light on the sensors doesn't stay illuminated when they're set. In order to turn off a tripped sensor, u have to slide the battery cover off. The switches are pretty small. The batteries could be regular ones, but maybe these (I call them watch batteries) last longer idk. You also need to have 3 AAA batteries for the keypad becuz they're not included.(not a negative just a need to know). They could've come with the warning stickers for display, but I'm going to order them for a few more dollars. But that's it. Great price for sense of security and deterrent. Product isn't flimsy. Glad I purchased