No instructions. Range stated on the box as 200 m, not 800. And a detached component that looks like a neon tube. Peter Jeremy confirmed, specifically that it's an NE-2. What's that for? And the battery connections look positively dangerous:
You have to know which way round to insert the (9 V) battery. Clearly it won't work if you put it in the wrong way round, but if you do so, will it ever work again after you put it back the right way round?
Experimentation shows that the three red buttons at the bottom create sequences of one, two and three beep tones. Presumably the others produce varying levels of shock. But look at the length of those metal pillars! And they're the only ones. Also there seems to be no way to turn the collar receiver off, and it annoyed me by beeping every 5 minutes or so. Clearly it wanted the battery to be removed to prevent discharge.
I've seen a lot of junk on eBay, but this one takes the cake.