OD High Performance Twin Springs with Vibrant Purple and Red Anodized Colors! You can enjoy it in a variety of colors and color coordination, as well as a focal point. The OD High Performance Shock Spring Series has a total of 6 different types. There are 3 types of spring rates each of the twin types with a wire diameter of 0.05 inch (1.3 mm) that focuses on the front line tracing performance and rolling, and a helper spring diameter that uses a diameter of 0.05 inch (1.2 mm) with a focus on traction performance. The 0.05 inch (1.3 mm) line diameter series has a free length of 1.0 inch (25 mm). The quick feature allows you to quickly load the load onto the tire and turn it into a grip. The 0.05 inch (20 mm) diameter series uses a super short type with a free length of 0.05 inch (1.2 mm) and a helper spring. This allows for a greater amount of rebound against spring rates to help improve grounding, and improve traction.