The granit x plus 54 borrows many of the features of it39s mega tough brother the granit extreme 59 the parabolic 13mm square section shackle is produced from hardened steel making it massively resistant to cropping and twistingtechnology 13 mm square parabolic shackle patented double bolted shackle in the lock body abus power cell technology patented offers highest protection against hitting and pulling attacks the shackle the case as well as supporting elements of the loc