As always, I recommend this product for workout. It didnt hurt that I only paid $10 for these bad boys either! One 10mm Titanium coated Dynamic Driver, and four Knowles 30095 Balanced Armatures lie under the shell on each side. Loved the satin fabric and easy, walkable wedge. I love it and thinking of ordering a second one for a space inside my backdoor for winter time to help dry gloves & scarves. I bought them expecting not much but still had some hopes for the features that were advertised. The only thing that worries me is the joints are welded but the solder (or whatever they used) does not go completely around. One of our bikes fit fine, but the other, a Cannondale Catalyst 4 mountain bike, doesnt fit fine. I am amazed, these things have big sound the mid and high range is excellent. I bought a size 7-9 for my 6.