The first SR-Λ (lambda) series was introduced 30 years ago, and now (Sep 2010) the SR-407 has accomplished further evolution with its new sounding body (sound element). The conventional sound element has employed simplest structure so that the widest possible film diaphragm area can be effectively used in comparison with its external size. Taking advantage of the conventional feature, the new sound element has been packaged in a tough resin case. Thus the new sound element has cleaner sound and more accurate sound image. Also, the new thin-film material are almost free from stretch from temperature or humidity, enabling both the rich, deep low-frequency and delicate high-frequency sound. Type Electrostatic, Open, Oval Sound Driver Frequency Range 7~41,000Hz Capacitance 110pF (including cable) Impedance 144KΩ (including cable at 10KHz) Sensitivity 101dB/100V rms Standard bias voltage 580 VDC Cable 2.5m, 6 strand, Wide format, Low Capacitance Weight 515g with cable 340g without cable Total Weight in Retail box 800g Standard Earpads EP-234BR Compatible Earpads EP-234 series		Japan Made. Highest manufacturing standard Japan Warranty Supplied by Authorized Resellers in Japan. 1 year Japan Warranty from the day we sent your parcel. We can help you liaise with the maker in Japan. You will pay for postages to/from our Japan office. Singapore and Malaysia buyers can bring/post to us locally. We will deliver FREE to/from Japan. Return postage chargeable. Recommended driver units, SRM-727, 727A, 727II Full range SRM-600 Limited Vacuum tube SRM-007t, 007tA, 007tII Vacuum tube SRM-006t, 006tA, 006tII Vacuum tube SRM-323, 323A, 323II Solid State