A spiral arch that comes in 20 or 30 linear feet (if the arch was a straight line). The bases can be moved, so the measurement can adjust a little but general measurements for the 20ft arch are 8 feet wide and 8 feet tall. It’s perfect for a small doorway and about 2 people will fit under the arch. General measurements for the 30ft arch are 15 feet wide and 15 feet tall. It’s perfect for 2 double doorways and about 5-7 people will fit under the arch.