One Convertible Double First Base from Soft Touch with this 15" double first base, both the runner and the first baseman have extra space at the base, thus reducing the chance of injury. Base Size is for high school and adult baseball. Base manufacture delivers durability and safety. 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. First Base Set includes: (1) 15" Double first base - non-release type, (1) Convertible tee which fit easily into the base, (1) 12" spike to secure double first base, (1) Spike-down disk to anchor double first base.