Intended largely for compressive toughness exams on rock, concrete as well as other substantial compression samples, this product steps axial strain on reverse sides with the exam specimen, and also the output is a mean of The 2 readings. Gauge Lengths: twenty five – 200 mm Basis for Continual Improvement: https://www.nathanisoconsulting.com/iso-iec-19770-12017-certification-consultant.htm