Soft Touch Convertible Double First Base Set includes: (1) 15" Double first base non-release type base, (2) 15" progressive release bases, (3) Convertible tees which fit easily into each base, (1) 12" spike to secure double first base, (1) Spike-down disk to anchor double first base. With its standard size, 15" double first base, both the fielder and runner have space, preventing collisions and injury down the line. The other "progressive release" design keeps players safe and prevents cuts, bruises, and broken bones caused by poor sliding. Complete baseball base system perfect for high school and adult baseball. Convertible Soft Touch bases deliver maximum durability, safety, and versatile, and easy installation. Bases made from cut-resistant polyurethane. Convertible bases include convertible tee and install easily over any existing 12" spike or 1 1/2" sleeve mounting system.Double first base anchors with a disk and spike mounting system.