Tandy Leather 1373-12 Double Cap Rivets Medium Nickel Plate | 100 PackNickel free. Extra Small: Cap 1 4" (6 mm), Post 3 16" (5 mm), Base 1 4" (6 mm)Small: Cap 1 4" (6 mm), Post 1 4" (6 mm), Base 1 4" (6 mm)Medium: Cap 5 16" (8 mm), Post 5 16" (8 mm), Base 5 16" (8 mm)Large: Cap 5 16" (8 mm), Post 1 2" (13 mm), Base 5 16" (8 mm)Steel. When only the best will do, these rivets offer the finished look that only double cap rivets can. Use setter #8100 00 and anvil #8056 00 or setter kit #8105 00.