I absolutely love my mobile patio planter! However once you place soil into the planter the weight increases greatly. The soft nature of the wood used to construct the product is not dense enough to to firmly hold the threaded insets where the casters screw into. Unfortunately I had to modify mine by purchasing leg braces and casters to attach to each brace. I then attached one to each leg. The casters sold with the product are just fine! Nothing is wrong with them, the softness of the wood was unable to support the brass colored insert that the caster screwed into. I highly advise the manufacturer to reconsider a different method to attach the casters bc the current method cannot support the weight of soil in the box.