ALLOWS USER TO CREATE A PERFECT FIT WITH A UNIQUE CUSTOM FIT DIAL; DESIGNED TO PRODUCE A PERFECT SEAL\, WHICH ALLOWS THE VARIABLE MATCHED TRANSDUCER TO DIRECTLY COUPLE WITH THE EARDRUM; SPECIALLY PADDED CLOTH-COVERED CORD SERVES AS A WRAP AROUND FOR PORTABLE DIGITAL MUSIC PLAYERS; FREQ RESP: 10 HZ-20 KHZ; IMP: 16_; SENSITIVITY: 108 DB SPL; 4-FT STRAIGHT\, DUAL-ENTRY CORD; INCLUDES 2 CARRYING CASES-SOFT LEATHER CASE & HARD CASE; NO-QUESTIONS-ASKED LIFETIME WARRANTY