For a smallish umbrella, this product works well and seems fairly sturdy.  It's big enough for me and a friend if we're right close.  It's made here in Oregon, so the company understands wind and rain.  I've yet to use it in big enough wind to invert it, but I own another ShedRain, a golf umbrella, and the overflap to let wind out works fairly well.  You can still get blown around a bit but I don't get knocked off my feet, either.