Heavy Duty Vinyl Bases are official size. Rugged, durable, and perfect for adult play. New polyfoam inner core allows for maximum shape retention along with a great "soft landing" cushion. Inverted sewn corner seams and double-thick top are designed to last. Covered with 100% nylon-impregnated vinyl covers that are both weather and water resistant. Each set includes packed 3 bases with 6 spikes.