This is the Team Integy Four Pack of Piggyback Shocks for the Traxxas Revo. FEATURES: Blue anodized shock bodies Aluminum construction Threaded shock bodies Team Integy logo and web address printed on the piggyback (reservoir) The piggyback design is built to reduce air bubbles and provide additional shock oil volume. Comes with two 20lbs rate springs (red) and two 25lbs rate springs (blue) Blue anodized inboard shock mounts Assembled with two hole pistons, but the shocks are not filled with oil. INCLUDES: Four assembled shocks (shocks comes without oil) Four, four hole shock pistons (two holes come installed) Four shock bushings Four 3mm X 10mm allen head screws Four 3mm x 15mm countersunk head screws Four 3mm X 3mm set screws Four piggyback (reservoir) foam inserts Four o-rings Four aluminum spacers Two aluminum inboard shock mounts REQUIRES: Team Integy recommends 90 weight silicone oil for the front and 110 or 120 weight for the rear. SPECS: Length: 4-1/8" (105mm) Diameter: 5/8" ( 16mm) COMMENTS: For replacement shafts, order INTC1629. For rebuild kit, order INTC1630. For plastic rod ends, order INTC2514 IntegyPart INTT3102BLUE