Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Works perfectly!

I've tried 3 other FM transmitters and none of them worked at all. Something about a metallic film on the inside of my windows that's blocking the signals. But I tried the XtremeMac and it works great! Perhaps due to it having the external antenna? I only give it 4 stars because it has a better sound when I switch to mono mode vs stereo, but hey, none of the other transmitters worked at all.