3 Section Insert-(ELS-SED11162) offers a thoughtfully designed, durable resource for hands-on learning. Gratnells 3 Section Insert - From trays with protective clip-on lids and tray inserts for science equipment, to wide wood trays for long glassware, Gratnells has everything you need for science storage. No wonder Science Technicians say that for school Prep Rooms, nothing even comes close to Gratnells!.