I was hesitant in buying this in the beginning as I was not sure if the weight is going to be sufficient to hold my umbrella and also how flimsy it could be. The product is made of high quality plastic and is pretty heavy on its own. Love the stability it is providing to my umbrella even in some windy conditions. I filled them with just water (and sand). Highly recommend to anyone looking for a high quality umbrella base.
Be careful. I bought 4 sets for my umbrellas but the clips don't fit. They are a 1/4 inch short and don't reach the holes. I have BLUU Redwood 10 FT Square Patio Umbrella Offset Cantilever Outdoor Umbrellas with 360° Rotation Device and Unlimited Tilting System & Cross Base