Note: Prior to purchasing, measure your original springs from hook end to hook end, disconnected from your trampoline, and completely compressed. Designed to offer high-quality steel, thick steel gauge, and multiple coils to provide durable and reliable performance. Trampoline springs are made of carbon steel with zinc plating to help protect against corrosion and rust caused by moisture and oxidation. Features high strength, good flexibility, uniform tension, and a smooth surface. Suitable for various sizes of trampolines, including large, medium, and small models. Specification: Material: 70# Carbon Steel Wire Diameter: 3.0 mm Size Chart: 3.5 Inches - Overall length: 9 cm (3.54 inches); Max diameter: 7.5 cm (2.95 inches) 4.0 Inches - Overall length: 9.5–10 cm (3.74–3.94 inches); Max diameter: 7.5 cm (2.95 inches) 4.5 Inches - Overall length: 12 cm (4.72 inches); Max diameter: 7 cm (2.76 inches) 5.0 Inches - Overall length: 13.5 cm (5.31 inches); Max diameter: 7 cm (2.76 inches) 5.5 Inches - Overall length: 14.7 cm (5.79 inches); Max diameter: 7 cm (2.76 inches) 6.5 Inches - Overall length: 16.7 cm (6.57 inches); Max diameter: 7 cm (2.76 inches) Package Includes: 1 x Trampoline Spring (7 Pack) Note: Please allow slight measurement deviation due to manual measurement.