Although it has no realistic connection to the Yashica of photographic fame, it still bears the name but as to who actually manufactured it, I have no idea.
It is actually a perfectly decent speaker; I ran an audio file recorded on a Contax i4R through it and was genuinely impressed by the result. It uses a rechargeable Li-Ion battery as its power source and has a multitude of connections including one specifically for the iPod/iPhone. If you pop in a USB stick or micro-SD card containing some of your favourite music and switch it on in the dark or low light, it emits a pleasing, blue glow from beneath the unit. Frequency response is perfectly adequate as is the '3D' effect. As soon as I find an old USB1 to USB1 cable, I'll attach it my PC and give its sound quality a real test.