K-Tech Mini Portable Speaker, 3W Line-in Phone Speaker with 3.5mm AUX Audio Interface, Plug and Play for iPhone, iPad, iPod, Tablet, Smartphone

I use this to improve on the audio from a small shortwave radio. Its frequency response is much improved over the stock speaker in the radio, making listening more pleasurable. It recharges quickly using a USB-C cable. I reccomend it for anyone who has a device with a small speaker and has a standard 3.5mm audio out jack, and wants to improve the audio.Note that is not a wireless Bluetooth speaker. It plugs directly into the speaker output jack on your radio, MP3 player, or other audio device. Its volume is controlled by the volume control of your audio device.I have not tested the battery life and the size of the battery is not specified. However, in my use so far, it seems to have enough battery power to last quite a long time. It takes about 45 minutes to recharge.

Is the audio quality good? Of course not. It's the size of a golf ball and inexpensive. But it works, and all you have to do is turn it on and plug it into the auxiliary jack of the device of your choice! It's actually plug and play, unlike a different device that looked very similar and CLAIMED to be "plug and play" but actually requires a Bluetooth connection to use. This thing, you literally just turn it on (it arrived to my house with a usable charge in the battery), plug it in, and control the volume using your phone or computer or whatever it's plugged into. That and the fact that it comes with a little charging cable (micro-USB), this thing is exactly what you want if you're looking at these types of speakers in the first place.

Clever design that provides mini external speaker with decent sound. Great for travel or office desk

Was great for a week. Used for audio for teaching videos. Worked fine with phone and with laptop. But battery seemed not to hold charge for long. If I tried to charge while using there was some static at intervals. After not using for a few days, I tried again - couldn't get to work with phone or laptop. Thought I found a great solution to limited volume from phone - Disappointed! UPDATE: Amazon promptly sent replacement. It is working so far, but only on first week. Like it, hope it keeps working.

For some reason, when I connect this little speaker to my tablet it doesn't respond to the volume controls. It is set on loud, and there it stays. The battery also doesn't last very long. It's a great size and easy to connect, so I wish I liked it better.

Works like a charm! Easy to use,does a great job for its price and small size.

I got this to use on my little Raspberry Pi computer that I have retropie on. It is loud like reviews say, but once I adjusted the level it has very good sound. Was what I wanted!

This thing is junk. The sound is very tinny, hissy, and the connector makes noise at even the slightest touch. It's cheap, which is nice, but you get what you pay for.