Cell Phone Signal Strength Booster Antenna for Cars and Trucks, Car Mount Passive Repeater Antenna - Automotive Reception Amplifier-Wireless Verizon AT&T Sprint, Tmobile, MetroPCS 5G 4G LTE by Cellet

These passive antennas work as they should! People expect them to pull a signal in out of thin air; well, they don't exactly work that way! The antenna only increases the signal that's outside the vehicle into the inside of the vehicle. They do not improve signals in weak areas! They mostly strengthen the signal inside the vehicle from the outside; the signal has to be available for this to occur! They adhesive quality is really good; the antenna sticks very well to glass surface. Allow them a good length of time to adhere, about 12 hours before you go flying down the road!

I don’t know why I was expecting when I purchased this - I was looking for something to help strengthen the signal at work but this didn’t do it. I tried different places in the office and didn’t notice any changes in my phone signal .

Increased T-Mobile reception from 0 bars to 1-2 bars, indoors (home), in one isolated area (say, a couple of square feet). Trust me, it's great achievement. I tried different phones with no luck, and was almost ready to buy a re-transmitter (they typically cost north of $150).Caveats:1. I first attached both pieces to the opposite sides of a window, and got no signal improvement. It was pain to remove them, I thought I'd break the windows. The 3M thing is "extra-hard" grade, which is probably permanent once it fully dries out. I used a sharp knife to carefully "spoil" 3M around the perimeter, and then applied constant pressure for a minute, so it gradually detached without breaking my window. Beware. Don't use included 3M until you're certain you've found best position. Use a simple scotch tape for experiments. Note: car windows are much stronger, I wouldn't worry about them. I'd worry about house windows.2. It took me maybe 5 minutes to find a good spot and orientation of this thing. Turned out to be fully indoors! Attached to my monitor stand and pointing to the window at sharp angle.With all these caveats, it's still 5 stars due to the value for the price.Even if it wouldn't work for you at all, this thing has a good chance of working and considering the price of "experiments" with other equipment it's worth trying! It's kinda unfortunate to see such a low average review score for a thing that can work! (but maybe not always/not for everyone), just because of plentiful of 1 star ratings from people for whom it didn't work.If you're ready to pay significant moneys for "proper" solutions (such as buying an active re-transmitter, or changing phone provider, ...or maybe even moving?), I'd say give this passive repeater a chance.

What all can you expect for five dollars? My friend and I like to drive around and play Pokemon go, but she gets disconnected a lot. I work in remote areas, so I was looking for a way to get cell signals farther out anyway.I know some radio dudes, and they all told me there was no way this thing could actually do anything I tried this thing out, and it seemed to help... maybe... in one spot in town, but we decided it wasn't really doing anything. I mean, it wasn't hurting, so I left it on for a while, but there was no way it was actually doing anything, right? Turns out it was hurting, because the spot I put it in meant that when I tried to wash my windows, there would be a big squeegee drip going down the middle of the windshield... Time for this thing to go. I ripped it off, and pulled up the tape on both sides.Turns out there is some sort of circuit board with a lot of coiled wire on the inside one. That's... well... if you were going to make one of these so they did something, you'd need that... I picked up my friend, and we drove around to play our game. half the spots we'd found since I got this antenna suddenly didn't work for her at all, and were a lot harder for me to connect with too. I guess it was working.On the package, they note that if there is no cell service at all, this antenna will not be able to do anything, and even in areas where there is coverage, it supposedly will only add half a bar. I guess it was adding half a bar in some places around town.A lot of users got this for their homes, since it says that it can be used there too. The package I got said "For Vehicle use only." I'm not sure if ones for home use only exist or not. Antennas like this, if they can do anything, need to have their inner part and their outer part placed a specific distance apart. Auto glass tends to be a thin single pane of 1/16-1/4 inch thick. Home windows tend to be double-pane, with 1/2 to 2 inches between the panes. If you live in an old house with single pane windows, the ones for automotive use might work there.

UPDATE: While this didn't work for me with T-Mobile, I have been beta testing the Starlink DTC (Direct to Cell) service through T-Mobile and this does a great job of bringing that DTC signal into my truck. With this, I don't need to make sure my phone has a clear view of the sky as long as this antennae does. I'll give it another starNote: other user's experience may vary.This did not work for me at all. I have T-Mobile and while my phone is capable of 5G, most of the service in my area is LTE. There are 3 dead zones on my drive to and from work. Between 1-3 miles each. Placing my phone up in the windshield helps some, so I know there's signal out there. But with this antennae, there was no change.It does look cool on the truck, and it's cheap enough keep it on just as an accessory.