We have a water bottle in the market.
Recently we found an almost identical water bottle in a store.
The cap is totally identical to ours, including the internal mechanism of the cap. The only difference is the body of the bottle which shape is just slightly different.
Their product does not seem to have a patent or at least they don't disclose it in the item.
we don't have a patent either.
Is there anyone here at risk of being suit in any way? Is there a copyright infringement? What are our risks in this case and what determines who has the upper hand?