Universal Security Instruments9-Volt Battery Operated Photoelectric Smoke and Fire Alarm, Model SS-901-LR

Nice smoke detectors. We live in a small town and ordering these were cheaper than paying for gas to go purchase at a store. Nice product.

I purchased several of these to update my house. Everybedroom and hallway has this model installed. I purchased ten ,it took me less than one hour to install all of them. Great product with loud piercing siren to awaken even the most sound sleeper.Compact and very easy to install.

Had a problem with the first one received as it wouldn't stop its ear piercing alarm with the battery attached. So,I've returned it and Amazon has replaced it. The new one appears to work properly and so far I'm pleased with it. Since it tests OK, it should do the job.

Price : GreatPerformance : Seem OK, test without issuesBuild: Fairly poorly made, but that's expected from the cost. That being said, they install easily without issue.

UPDATE 4/11/2017: I had to go from my original 5 star rating to 1. Yesterday, this started going off for no reason, I was not even cooking anything, nothing at all going on that would normally trip an alarm. Yet once it started going off, even covering the vents or taking it outside would not shut it up. I took batteries out and replaced them several times...goes immediately to alarm.This is only 4 months after I bought it. Not worth spending any money shipping this back for warranty, it was not expensive enough to bother. But now I have to buy a new one, a better one I should have bought to begin with. This was money flushed down the toilet :( This is my original review, so maybe you can better understand my disappointment. Sorry:This smoke detector certainly is cheap enough. It looks pretty good too. It comes with a heavy duty 9 volt battery, but I installed a name brand alkaline instead. Sometimes when a manufacturer generously includes the battery, they are cheap and don't last very long. The supplied battery may be fine, I will never know. Anyway, it tested okay and the alarm is plenty loud enough. Like others have mentioned, you hope it never goes off. Your house burning down can't be a very pleasant experience.

The last smoke detector would chirp for about 10 minutes with every shower. That was beyond annoying when it would wake up my three small children every morning while my hubby got ready for work. For this reason I purchased this photo-type sensor detector. It is perfect and hasn't once chirped for the shower! Ahhh, sweet silence!

I purchased this December 2019. It is now 29th of August 2020 it only lasted eight months and now It has quit working properly so, I have to replace it,

How this is built and the instructions don't give me much confidence - it seems they did both with the bare minimum needed.The instructions don't tell you, much less show you, how to change the battery - though it is obvious when you have the alarm in your hands. See photo.There is no indication on the base for how to orient it (see pic), and it's not mentioned in the instructions - I'm kinda short so I want the button on the bottom. I figured it out and marked the 'top' of the base with a sharpie. It does come with 2 screws and drywall anchors for mounting the base. Dunno why the instructions call this "a complete mounting kit". The instructions don't include use of the anchors.There is no indication how to orient the alarm when putting it on the base - again, I figured it out and marked the base and alarm with sharpie.The instructions say it comes with an anti-'tamper locking pin', but mine did not come with one. I wouldn't have used it anyway. Because...There is no 'silent' function.