Just as bleachers allow people to see over those in front of them, Lyman's reloading blocks allow for easier handling of cases in and out of the loading block. Allowing for easier access and a smaller “footprint” on your bench. Made of tough, durable polymer, the Bleacher Blocks are molded in three sizes to closely fit a variety of rifle cases. One size fits 223 size case heads, another fits 308 size case heads and the third fits belted magnum size cases. All hold 50 rounds.