Nothing to assemble. The headphones have an ambient feature (press JLAB LOGO BUTTON on right ear muff). I will likely only use these while mowing the lawn, and only the sd card, but the turn out speakers are a GREAT idea. I picked the XL, which fits size 11-12, per the ordering info, since the Large showed a fit of up to size 10. As a little bit of a germophobe, I like not having to touch them with my hands to put them on and off. The sole thinner than classics as well. My feet are happy and feel great after a days work. Let’s be clear, my husband does NOT notice shoes. For the first few hours I was doing some DIY and listening to an audiobook - they were OK for this, but having become increasingly irritated by the unnecessarily difficult to manage knobbly wires, I played some reference tracks (music Im very familiar with) and they were back in their box within a couple of minutes - staggeringly bad! Im very happy with these earbuds.