5 Hardwood Smooth Unfinished Wooden Rings Hardwood is either Birch or Maple 2" OD, 1" ID, " thick, 63.5mm OD, 38.1mmID, 12.7mm thick Rings are smooth but unfinished and may need additional hand sanding in some cases. Can be used for many craft projects such as Crocheted Christmas wreath ornaments.