Logitech UE 900s Ultimate Ears Noise-Isolating Earphones (NEWEST 2014 VERSION) Impedance: 30 Ohms @ 1kHz Frequency response: 20 Hz  20 kHz Internal speaker configuration: 4 proprietary balanced armatures with a 3-way crossover Input connector: 1/8 headphone jack into any personal monitoring system. Warranty: 1 Year