I personally never noticed an odor - only really noticeable if you stick the shoe right up to your face - and as your feet will hopefully be on the floor and not next to someones nose, you should be fine. Please for your own sake look for a different set of boxes I loved the fit of the Trekz. Other noteThe Flip 4 is terrific for exceptional musical detail at a quiet setting (office) or loud open air setting (like the beach) the music detail carries far with out being overly disruptive, just don?t expect that bass like the charge and above modelsSome say the Charge 3 is the one to get, but for me I?m satisfied at the moment and will wait for future Charge Models or equivalent models to come out. So, since I had such good luck with the previous product, I decided to go with their new generation product, the Duo. Was a very great product until recently. I can charge while I?m laying on the couch texting or using FaceTime. It isn?t strong enough for me. The top is not attached to the bottom part of the case but still stays on snugly and securely. My husband loves Crocs, I just couldnt get behind them .