The SR-003 is a 5-pin PRO bias type in-the-ear earspeaker, and can be used by connecting to a driver unit having 5-pin PRO bias output socket. Also, the inner type structure of the SR-003 enables you to enjoy excellent electrostatic sound readily without covering your ears. The SR-003 connects to STAX driver units or adapters equipped with 5-pin type PRO bias output- The Stax SR-003 is the home audio version of the S-001MK2 In-The-Earspeakers with a 5-pin plug connection suitable for any Stax driver unit or adaptor with "Pro" capability. - Extremely comfortable lightweight soft tipped pads for inner ear comfort and extended bass response.- Even lighter diaphragm reduced from 2.5 micron thickness to a remarkable 1.5micron resulting in further resolution, transparency and purer listening pleasure.- As the SR-003 is In-The-Ear type Earspeakers, comfort is enhanced leaving the ears clear of all external restrictions and perspiration that may result from heavy earpad types.- Stax are confident that the SR-003 In-The-Earspeakers will provide every listener with satisfaction and Stax unsurpassed sonic superiority.Specifications:- Type: Electrostatic canal type In-The-Earspeakers, push-pull driving- Frequency Response: 20-1kHz 2dB, 1kHz-20kHz 4dB- Capacitance: 44pF with cable, 17pF without cable- Impedance: 360K ohms/10kHz- Sensitivity: 111dB/100Vr.m.s. /1kHz- Maximum Sound Pressure level: 119dB/1kHz- Standard Bias Voltage: 580VDC- Pad(Fitting Rubber): Made of silicon rubber (2 sizes, M and L)- Cable: 6-core parallel/1.5m- Weight and Size: 28g with cable / 12g without cable, 28mm diameterWarranty: 1 year full Japan warranty.We Appreciate to COMBINE !!! We will send your items together.Please contact us.!Warranty:1 year Japan warranty!