the pro 4 kit is 109.99 and comes with a 3mm chassis,3mm top deck,and 3mmk front and rear shock towers.the stock pro 4 kit is 2.5 mm carbon fiber that is what they call component grade.i use quasi isotropic which is layed at 0-90-45 degrees to increase torsional strength.component grade is layed at 0 and 90 degrees.i countersink all the holes a little past the tops of the heads to ensure that everything is pulled into location.sometimes you may aquire a minimal tweak if the molded plastic parts vary but usually the chassis pulls them into place.hope this helps
jason