G Keni Smart Anti-Theft Bike Alarm, Bike Tail Light Rechargeable, Warning Electric Horn, Bike Finder with Remote, IPX5 Waterproof Electric Mountain/City Bike Accessories

Every once in a while you find something on Amazon that surprises you with the quality and the value of the item. This is that item. I didn't expect much when I ordered it but I was desperate. I had just purchased my dream bike and I was not about to lose it to some low life, piece of %$*@, bike thief. Now along with a Kryptonite U lock and the heavy chain combo lock I can finally feel comfortable away from my machine. The folks at K&K International Co. Ltd really put some thought into this little engineered marvel. It simply works perfectly every single time you set it. Extremely simple to install, I had to modify mine just a bit to make it fit on my tadpole recumbent and am I glad I took the time. For less than $25 you get a very high quality tail light, a remote and an alarm that I am sure would cost you $150 if you could find one! The alarm is the perfect loudness, a not so bad sound effect and a warning sound that helps a lot if you park it in a windy situation or crowded bike rack that could be unknowingly bumped by someone. If you bump it it chirps at you, if you continue to mess with it the main alarm goes off. The sensitivity is set to perfection, the remote works so well and is so convenient I am just amazed. This is the one to buy, a can't miss and under $25?! Buy this one and start sleeping at night knowing your expensive machine is safe. Thanks K&K for this superb device!

Very happy with this purchase. Functions as promised. Alarm is very sensitive and extremely loud. Under seat mounting was a bit difficult, but quick removal by thieves would prove difficult as well. They do include a post mount as if you need a simpler option. Light is bright and horn is effective with 3 different sound options. Overall great product.Update: purchased again for new bicycle.Pros: Upgraded model has new features including more horn sounds, adjustable volume and alarm sensitivity and light sensing feature that will automatically turn on tail light at night when bike is in motion .Con: New model uses thumbscrew instead of allen screw to secure light to mounting bracket making it easier to remove. I prefer the more secure allen screw.

It was difficult to attach at first, but fortunately the second alternative (the "third time") was the charm, and it was easy. This light/alarm is an incredible buy, maybe the best in all of my Amazon purchases. The alarm is a loud 115 decibels (just shy, I think the product info related, of the noise required to cause permanent hearing damage, and I believe it), but it is not so sensitive that it goes off unless someone is definitely messing with your bike (in my case, an expensive ebike). And everything works, even the motion-sensor brake light! For 20-or-so bucks, this alarm is a steal!

Alarm:Once the alarm is set, any movement of the bike at all will set it off for 30 seconds and remains in alarm mode until it's deactivated or dies. The alarm can be shut off with a press combination of the blue button if you set it up, but if you don't set it up I'm pretty sure all it does is turn the alarm on. I don't use it so I don't know. As for loudness, it's LOUD. You'll very easily hear it if you go into a store. It's about as loud as a car alarm, but not quite.Light:It's not the brightest tail light I've seen for a bike, but it's still plenty bright. Covers 180 degrees easily, although loses brightness towards the extreme side angles like you'd expect. Has three modes: slow blink, fast blink, steady. Makes a very quiet noise when the light is on almost like the PCB allows for a tiny bit of current to go into the alarm speaker. You can only really hear it when trying to, but I guarantee this decreases battery life.Remote:The remote range is easily as advertised and you can extend the range a bit by pressing it upwards against your chin before pressing a button as your head will act as an amplifier. It's very light and feels cheap so I'm not so sure how long it'll last. I have no experience with this company so I don't know if they'll stand by their product and replace the remote. Don't lose it. The buttons are tactile and once you know which one does what you can easily feel for the button without looking.Hardware:Lots of adapters included. You can mount the remote to your bike, but it's all plastic on plastic and I can't see the mechanism holding up to too many removals and additions of the remote to and from the adapter. I opted to just put it on my keychain, but considering you can use this as a horn maybe that's something you'd want to use. Maybe use velcro instead.The way the light is mounted is by an adapter that tightens in between the rails of your saddle. If you have round saddle rails like most saddles do then this adapter works fine, but if you have carbon rails that are oval it doesn't fit that well. It still worked, but it's slanted to one side and isn't completely secure (tilts up/down slightly). The tail light slides and clips on to this adapter and can then be screwed in if you want extra security from it falling off or being taken off. I screwed mine in and it's rock solid.There are a couple other adapters that I haven't needed to use. Included zip ties aren't great.Battery:Just a quick note here, but the manual and website say it's 700mah, however, it says 800mah on the tail light. Either way it's still plenty of capacity for a tail light, but there's a discrepancy there nonetheless.Compatability:Beyond the oval rails that I mentioned, there's one more thing to mention. This light does work with a saddle bag under it without any problems at all. Light is still visible and the saddle bag is still far from touching the rear tire.Overall, it's a pretty great product. The alarm and remote features work well, the battery life and remote range is good, and the light is plenty bright enough. I'm deducting a star though because of the battery discrepancy and cheap build quality with everything being plastic except for the screws.IMO the best use case for this product is for someone who stops at public places a lot and wants their bike to be light without the need of carrying a bulky high security lock. Combo this alarm with a small lock or two that lock the tires in place so it can't be ridden away and then you should be set as long as you're alert to the alarm going off. Cutting even a cable lock should set this thing off.I'll update this review later with a picture of it on my bike.EDIT:Added three images. The light comparison photos are between this one and the common and often rebranded B015IEJ0GC taillight.Still happy with the product after a little over a week of usage.