The reason I'm writing now, two years after purchase, is, I broke one of the wheels. I proceeded to order the wrong replacement, so I emailed them pictures to ask for the right parts. They wrote back asking for the serial number to get the right unit AND to see if it was under warranty. (Hadn't even occurred to me.) Turns out it was, they're sending me the wheels, they're refunding me for the wrong part, AND included a link for the Puri-Tabs which I didn't know they provide for the life of the ROWER! They're also replacing all eight wheels even though there's only one broken one.
From a fitness perspective, the WaterRower Natural works 84 percent of your muscle mass, helping tone and strengthen your muscles while burning far more calories than most other aerobic machines. The exercise is also low impact, as it removes all the body weight from the ankles, knees, and hips, but still moves the limbs and joints through a full range of motion--from completely extended to completely contracted.