This chain maille is made of round, butted rings. Their blackened surface provides some protection from corrosion. We call this type of chain maile Butted Mild Steel Blackened.
A hauberk is a long-sleeved chain maille shirt that reaches to the knees.
Details - chest circumference: approx. 140 cm when fully extended. Your chest should not exceed 125 cm when wearing your gambeson. - length from shoulder: approx. 114 cm - arm length from armpit: approx. 55 cm - ring thickness: 1.6 mm - interior diameter: 8 mm