Instruct: Classify the given review as either positive or negative.
Query: Best rear light under 10 bucks.

This is the best rear bicycle light under $10. The battery life lasts forever. It also uses AAA batteries and not some weird size battery that costs 5 bucks at Walgreens. It's waterproof and has 3 mounting options; clip, seat post, or the rear strut. It's bright, and you'll be seen from blocks away. Hands down you wouldn't need to pay more for a rear light. I Highly recommend this product.