Instruct: Classify the given Amazon review into positive or negative sentiment.
Query: Effective (To a Degree)

Pretty comfortable and adjustable. Great for taking a nap when it's not possible to get the room 100% dark. However, I am a bit disappointed because mine has already started to come apart, and it's been only 4 months. May buy another one, but first I'm going to try other brands. Sigh.