In MYST Nail3 is made with receiver that was used in Sleek Audio SA6 cult headphones.
Just as all the other models from Nail series, Nail3 were made in small metal body, that can be inserted in almost all ears without any inconveniences. We use silver plated copper (Arg/Cu=7/3) as the conductor in our cables and 3.5mm Amphenol or Neutrik jacks.
Speaking of the sound, Nail3 is a bit different from Nail1 and Nail2 in terms of “softness”, so it's less aggressive and pushy than our other models. But this difference isn't global. Nail3 have both excellent step response and resolution, but at the same time they are so versatile because of their low impedance.
Moreover, their soft signature is a good point to buy them if you search headphones for calm music genres of for long-time listening, I assure you that Nail3 can play metal excellent too.