Thank you for viewing! Popular parts are sold as a set! 1️⃣ Aluminum Roller Set ① All Aluminum Bearing Rollers ② All Aluminum Bearing Taper Rollers ③ 2-Stage Aluminum Roller Set 13-12mm 2️⃣ Reinforced Unit Set ① N-04 T-04 Reinforced Unit (Red) ② N-02 701 Reinforced Unit ③ N-02 701 Reinforced Unit (Black) 3️⃣ Limited Wheel Set ① Mini 4WD 35th Anniversary White Tire & Blue Plated A Wheel Set ② Large Diameter Low Height Tire & Wheel Set ③ Low Height Tire & Y Wheel Set ④ Low Friction Small Diameter Narrow Tire (24mm) & 3-Spoke Wheel Set, 2 pieces 4️⃣ Barrel Spring and Spacer Set ① 5mm Pipe for 2-Stage Aluminum Rollers, 4 pieces ② Barrel Springs (Silver 4, Black 4, total 8) We look forward to your purchase!!