Each section combines track and roadbed into a single unit, with snap-fit assembly and plug-in wiring to provide instant railroad fun, A hidden locking feature holds sections securely together until you"re ready to take them apart, Easy to set up on any surface, including floors and rugs: No special tools, nails or boards are needed, A great system for Christmas, displays or permanent layouts, Twelve sections of curved 18"" radius track make a full circle; 16 Sections of curved 22"" radius track make a full circle, SKU: SPWS4676