BEWARE the wedge is super narrow but the strap is too big to hold your foot in place, seems like a twisted ankle waiting to happen for me personally so I returned them. The representative, surprisingly, told me the warranty process takes much longer than returning to the store, so he suggested I return it to Amazon. I had a pair for hiking in Scotland, brought another to Peru, one in southern Utah deserts and canyons, good for city walks too. I wouldnt be surprised if they went under from selling such great earbuds at too low of a price (usually around $40-$60). They were not comfortable at all. For me, the vamp was too big. The D9 unit is now of a IPX6 waterproof construction, which means it is protected from powerful water jets, but does not mean you can place this unit in a swimming pool or prolonged raining. Only problem I had was orientation of the top bars. just dont overload it. There are 3 USB slots on the charger, so you can charge a friends phone too if you are feeling generous with your amps.