Main material is 48.3mm steel tube. 5 parts for you to mount different style or size. often used to fly line array speakers. Layer Truss, main material is 48.3mm steel tube.They have 5 parts for you to mount different style and size.They are often used in big performances and project outdoor ,especially to fly line array speakers. Common Size:1*2m / 2*2m / 1.22*1.83m / 1.22*2.44m / 2.44*2.44m ...