The diaphragm film of the SR-003MK2, like the S-002, is designed to be thinner and more lightweight by approx. 15%. The SR-003MK2 is equipped with a STAX 5-pin PRO bias code and can be connected to any driver unit equipped with a PRO bias output socket. SPECIFICATIONS Type: push-pull electrostatic, canal-type inears Frequency response : 20 - 20 kHz (±4dB) Static capacity : 44pF (including attached code) Sound pressure sensitivity : 110dB/100V r.m.s. / 1kHz Bias voltage : 550V – 580V Ear piece : L/M/S size made of silicone rubber (M size equipped at factory shipment) Cord : 5-pin for STAX PRO bias, 6-core parallel, total length 1.5m Weight : 38g (including code), 12g (main part only) Dimension: 28mm (diameter) Overhead arc weight : 15g