EQ Acoustics Project Corner Traps grey

I don't know how true the promises are, as studying the subject further reveals the more problematic nature of lower frequencies - not necessarily a fit task for a piece of foam.

However, they seem to even out the room and decrease the lingering low end and even some reflections.

I'd say it's a good product for the money, but don't think it's going to solve all your problems in a small room.