Pretty Poor, Better Earphones Are Available
Let me start with the positives: good quality sound, deep bass and solid build quality - unfortunately it ends there. The earphones fit well initially but very slight head movements cause them to fall out constantly meaning utter frustration. When running or jumping, they become absolutely unusable. The microphonic noise (noise heard through headphones when the cable rubs on clothing, for example) is similarly infuriating. The sound isolation again is poor, as keeping a tight seal in your ear is almost impossible with the provided rubber seals. Would I recommend them? In a word: No. There are much better earphones available (particularly the Shure E2c) and while they may be more expensive, you will thank me in the long run.