The Prizm Deluxe protein skimmers are a decent buy. It is very slim line (can fit in small spaces) and is simple to operate.
Although it states that it can be for up to 90 Gallon tanks, I would use it for no more than 45 Gallon tank.
It can be a little noisy, depending on how loud you are used to hearing.
In all, this is a good economical buy.