Instruct: Classify a given Amazon review as either positive or negative.
Query: Yup, it's a filter.

I bought this filter to remove UV light from my images and afford an extra ounce of protection for my $50 lens. Let's face it; I have no way of knowing whether it works or not: I can't see UV! And it hasn't protected my lens yet; that's an insurance function. So yeah, it's working great! Fits well. Looks classy. Nothing to it. Yay!