1. Package: 200Pcs Springs. . 2. Material: Galvanized Steel. . 3. Compression Springs: -5.5x17.5 -5.5x38.0 -6.5x10.0 -7.0x12.5 -7.0x19.0 -9.0x35 -9.5x16 -9.5x19 mm (the quantity as the picture shows). . 4. Tension Springs: -4.0x79.5 -4.5x44.5 -5.0x20.5 -5.5x25.5 -6.5x22.0 -7.0x98.0 -7.0x51.0 -8.0x28.5 -8.0x31.5 -8.0x44.5 -8.5x36.5 -8.5x47 mm. (The quantity as the picture shows.) . 5. Usage: Widely used for automotive tools and engines, medical devices, large equipment, electronics and sensitive measuring instruments.