This is a Traxxas Promotion

FREE! $100 Value!
Big Bore Shocks with E-Maxx Purchase

Purchase an E-Maxx® (model #3906) from Steel City between September 1 and October 31, 2007, and you will be eligible to receive a FREE Big Bore™ shock kit (item #4962) by mail from Traxxas. The Traxxas Big Bore shock kit includes eight assembled, high-quality aluminum Big Bore shocks! Big Bore shocks are hard-anodized and Teflon®-coated for the smoothest operation possible and they feature internal diaphragms that help keep the air and oil separated for increased performance. These shocks also include our super smooth, long wearing titanium nitride (TiN) coated shock shafts. Big Bore shocks are completely assembled and include red, 2.5 rate shock springs, additional shock pistons and clip on pre-load spacers for quick ride height adjustments.

Offer is valid only for in-store purchases. Mail order and online purchases are not eligible for this offer. Offer ends October 31, 2007. Redemptions must be postmarked by November 30, 2007. US customers only. Go here for complete rules and detail
More specific info here.