As of June 21, 2022, all new D-100 and D-1000 conveyor dryers began shipping with lids that feature a hole (which is used for exhaust extraction). Our Exhaust Option will mount directly on newer dryers without any modification. If you want to add a powered exhaust option to dryers shipped prior to June 21, 2022, a replacement lid must be purchased. This item is for the replacement lid (choose from either D100 or D1000 versions).