However the quality of the tin is lacking as its a bit warped but it gets the job done. You shouldnt need an additional sound card or amplifier of any kind. Super nice stainless steel finish and is very solid. These are absolute junk. I was really nervous to put this in the water because its got some weight to it. Lasts for 3days of Moderate usage. I bought this product over 6 months ago and I just wanted to make sure I went back and left a review because Im very satisfied with it. I enjoy these and highly recommend purchasing them! Always pay the next day after wearing sandals but these things are awesome. Look much cuter than I would have expected a Naturalizer shoe to look.