Fully tested and guaranteed – no broken teeth or paper strippers. Has optical sensors to engage auto start when object placed in throat. NOTE – this item does not include a bin. There is a start switch (pictured) on base that is meant to engage when placed on base. You can use this without it, but must bypass the safety switch. Item is offered as a replacement cutter assy ONLY. Not returnable for missing bin. Excellent high quality machine not made this way today.