This speaker used my 5-year-old for his Sansa MP3 Player. The sound in radio plays is absolutely great! I myself have a speaker for my audio books and I must say that I like the sound even better here in this. The speaker is greater than is assumed on the basis of product photos, in any case we were doing so, but does not bother us. Three AAA batteries are included. Operation on AAA batteries I find very convenient especially for children, because the forgotten at this, identify the speaker so you can quickly change the batteries once just. We use, for environmental reasons Eneloop batteries. Vulnerability is usually the transition from cable to speaker, which is why we very careful that no train comes on to the cable. So we do not wrap it up and put the player on the speaker (and not let him runterbammeln) when we carry him. The speaker was a good buy, I would buy it immediately!