Prehma Perforated Plastic Impression Trays are disposable and feature keyway and sideway slots to ensure retention. These disposable impression trays also feature a posterior rim lock designed to reduce gagging or a secondary flow. Prehma Perforated Plastic Impression Trays are designed to capture impressions without distortion while being comfortable for the patient. Packing is 12 per bag. Features and Benefits Durable Rigid material for consistent, distortion-free results Enhanced Retention Perforations for better material grip Multiple Sizes Eight sizes available for a perfect fit Comfortable Design Anatomically shaped for patient comfort Versatile Use Compatible with various impression materials Hygienic Disposable and packaged in sets of 12 Size Package Contains MFG Models# #6 Small Lower 12/Pkg 490-0611 #7 Upper Right, Lower Left 12/Pkg 490-0711 #8 Upper Left, Lower Right 12/Pkg 490-0811 #9 Anterior 12/Pkg 490-0911 #1 Large Upper 12/Pkg 490-0110 #2 Large Lower 12/Pkg 490-0210 #3 Medium Upper 12/Pkg 490-0311 #4 Medium Lower 12/Pkg 490-0411 #5 Small Upper 12/Pkg 490-0511