Techncial data & main features: Stamping speed:18 20 thousand pieces/ Hour(Width of envelop≥ 130mm ) Postmark missing percentage:≤ 0.4% .Power supply:220V±10% 50HzPower consumption:≤200WThickness of envelop:0.1 9mm (Adjustable)Medium:postcard, B6-C4 envelopeAutomatic counting, auto stop upon block, sensor detetcting, store of counting number and accumulative number,envelop number can be reset, accumulative number can’t be reset.Position of mark and shape of the mark can be adjusted and stored by means of 4 switches at rear side of the display panel.Noise:≤ 75dB ( A )