We manufacture our volumetric pipettes subject to DIN EN ISO 648. Accuracy classes Conformity-certified: for higher accuracy, rapidly running out, with waiting time of 5 s (but shorter drain time), according to class AS All conformity-certified volumetric pipettes are equipped with a batch number. A batch certificate is enclosed to every original box. Standard type: aberrant from standard (class B) we provide a higher accuracy. Our pipettes have only the 1.5-time error margin of class AS. According to the standard no waiting time is claimed for class B. Calibration Calibrated to deliver = Ex The quantity of liquid delivered from the device serves as determination base for the graduation. Do not remove residual liquid by blowing it out (except with "blow out pipettes", which are named as such).