High speed SRA3 machines. 150 model features side-lay register board for improved accuracy. Graphic Whizard perforating machines all feature the unique adjustable-depth perf/score system. Sets can be part-perforated in one pass (ie 3 out of 4 sheets perforated, bottom last sheet left unperforated). Sheets are held in position by three sets of gripper wheels whilst being perforated or scored. Other manufacturers perforate and score on a single set of exit wheels, with the resulting run-off in the perforation accuracy