Rear carbon fiber and aluminum multi shock and push rod mount rocker arm.
Using these rocker arms, you do not need to change the rocker arm to change progressive rate - just change the mounting position.

Two red anodized aluminum bearing holders
two carbon fiber cams
four black 2mm button head screws
four silver plain nuts
four cone shape spacers
two silver flat head screws

The key to Revo suspension performance is the progressive geometry built into the rockers. Increasing progressive rate over the stock progressive rockers or long travel rockers is as simple as bolting on a new setting of mounting plate.
For more combinations of adjustments P1 to p3 and Long Travel.
Change from firmness to Soft to suit your racing need. (Can use different push rod give you more flexibility) (P1 to p3 and Long Travel mount plate are sold separately. )