These feature a set of Koss KSC75 headphones embedded into a pair of Peltor 105 headphones. They are lightweight and sound amazingly good. The Koss headphones, while very inexpensive, are often regarded as surprisingly good for their price. Placing them inside of the soundproof chambers of a set of headphones only improves their sound quality. The speakers are held in place by two vertical slots cut into the sides of the red plastic of the ear cups which allow them to sit closer to the ear, providing better sound. I had to play around with the slot in order to get the headphones close enough to my ears to sound good, but not so close as to put undue pressure on them. They are pressed to the front of the slot by the existing ear cup foam behind them. It's been a pleasure using them so far.
Inspiration and instruction from dsjackson1
I've been using my homemade hi-fi headphones for a week or so and while they sound great, I really wanted to eliminate the cord going from the headphones to the iPhone/iPod in my pants pocket. It annoyingly gets caught on things around the shop and could be potentially dangerous as well; getting pulled into a machine and whatnot. The solution I came up with was to attach an iPod Shuffle to the rear of one of the cups via a short cord. The Shuffle is ridiculously small and lightweight and has a (quite frankly, awesome) VoiceOver navigation system that let's you sort through the iPod's content very effectively without the use of a screen. The end result is clean, lightweight and self contained.