The Final Audio Design F3100 is an extremely small and lightweight, with a perfect fit and high sound insulation properties. Situated close to the wearer's eardrum and being highly airtight, this model delivers high resolution, a vast sound stage and clear bass tones. You can position the product to be at the back or at the entrance of the ear canal, and change the sound quality by choosing different earpieces. The F3100 have used an ultra small full-range balanced armature driver unit. An aluminium-magnesium alloy for the F3100 housing, which in turn is finished in a chic black anodic film exhibiting high hardness. The F series comes with an ear hook to reduce microphonics. The cable is high purity OFC. The PVC tubing has been chosen for its flexibility and has been finished with a rope-like texture to reduce microphonics. The earphone comes with a safe fit rings (for silicon earpieces, for foam earpieces) so you can use your earpiece safely. Specifications: Housing: Black alumite finished aluminum, Driver: Balanced armature, Cable: Black OFC, Sensitivity: 106dB, Impedance: 42 Ohms, Cord length: 1.2m. Accessories: Silicon carry case, Silicon ear piece (E type, 5 sizes), Foam ear piece (3 sizes), Safe fit ring, Ear hook.