Yellow Color,1500RPM, 3pcs of Clutch Springs & 1 Torque Spring
The lowest rated 1K Springs may give you a higher speed overall but will engage at a lower RPM on take-off. Hard to "climb the hill"
The 2K Springs will give you the greatest grabbing power and a higher RPM at take-off.Easy to "Climb the hills" but may be slower in speed overall
The 1.5K springs have the balanced performance.
Please Note: The exact performance of upgrade parts will be affected by many other factors