Large Round Bur Block - Black, Magnetic, 28 Burs Capacity, Diameter 2 13/16", Single Block. Steam and chemical autoclavable to 250F. Easily stores different types of burs. Can accommodate various shanks. Compact design saves space. Autoclave sterilize. The Large Round Magnetic Bur Blocks provide a way to conveniently store and organize different types of burs. Each block can hold up to 28 burs, including latch-type and friction grip burs.They feature a compact design that saves storage space. Autoclavable up to 250ÂF.Different #s and colors are also available.