get this one, don't get 980a
My ex-roommate has the 980a and I have the 580a. 980a is $10 more and it has two options instead of one seen in the 580a. The sounds from 980a and 580a is very similar. It has a very constant noise (no recording/repeating sound) and they both work well to sleep or drown out the noise from outside. If you sleep in a small, decent size bathroom, 580a is loud enough for daily usage. I have the 580a and I have to cover all the holes to minimize the noise. It can be loud if I don't cover all the holes. Overall, $40 is good, I just hope it lasts a while, like a year or two.
Rating: 5 stars