This is an optional Arrma Shock Spring Set. These springs are 84mm long and rate 56.6gf/mm; the higher this number is, the stiffer the Shock Spring is under compression; the lower this number is, the softer the Shock Spring is under compression.

Features:

• High-quality steel for consistent performance and long-lasting durability
• Designed to provide smooth and reliable Shock Absorber action in all conditions
• Available in a range of lengths and strengths to provide a wide variety of fast tuning options