Hollywood Impact Kwik-Release Double First Base has an advanced design that will compress upon impact and a waffle bottom design that adds strength and flexibility. For safety, the top of the base (white portion) disengages from the bottom base (orange portion) upon strong impact. The soft rubber nubs on top hold onto the top portion of the base but are soft enough for players to slide over without injury. Set includes: double first base, 2 standard bases. Base plugs and ground anchors are sold separately. Dimensions: 15" x 15" x 2 1/4".