Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Fantastic Sunglasses - Serengeti

These are fantastic sunglasses. I have been wearing Serengeti for many years and couldn't be happier with their 'performance'. I use them powerboating and snowmobiling where reduced glare is so important at higher speeds and for navigating. I also have a set of Serengeti 'Ronan' frames that fit a little less snug also with the polarized Sedona lenses. My next purchase will be 'Piza' frames with polarized drivers lenses (have worn the drivers lenses in the past too). I have been updating for styles and replacing for loss (unfortunately).Serengeti (Bushnell Canada) customer service has also been fantastic. On a set with metal frames one of the screws came loose allowing the lens to fall out (and break). Bushnell replaced the set of glasses no charge. On the new ones the screw tips were peened so they wouldn't come loose.Serengeti are pricy sold retail but almost half price here...and worth every penny.