Etymotic Research ER4SR Studio Reference In-Ear Monitors PLUS Blucoil Carrying Case PLUS Blucoil 6 Foot Extender - VALUE BUNDLE Type: In-Ear Frequency Response: 20 Hz to 16 kHz Sensitivity: 98 to 104 dB Package Contents: Etymotic Research ER4SR In-Ear Studio Reference Earphones / Detachable 5' Cable with 3.5mm Gold-Plated Stereo Plug / 2 x Pairs Standard 3-Flange Eartips / 2 x Pairs Large 3-Flange Eartips / 2 x Pairs Large Black Foam Eartips / Filter-Removal Tool and Filters / Shirt Clip / 1/4 Stereo Phone Adaptor / Blucoil Premium Earphone Storage Case / Blucoil 6 ft Headphone extender