Calibrated Steel Rulers. As specified in many International standards for the measurement of fabric width and length, also measurement and marking of fabric samples before or after testing. Supplied with ISO 17025 Calibration Certificates. Available in 12"/300 mm, 24"/600 mm and 39"/1000 mm lengths with metric and imperial markings. Flexible Steel tape measure 117"/3000 mm with ISO 17025 Calibration Certificate.