The new progressive springs marked as 7-9 are soft at the beginning of the compression (similar to hardness 7) but then they become harder as the spring is compressed more: 8 hardness in the middle, and 9 hardness at the end. These springs makes the car steer better at the beginning of the corner, but resist rolling in the middle of the corner because the spring becomes harder. Recommended for medium-high traction. Stylish black finish. Laser-engraved value on top spring coil for easy identification. Set of 2.