This is the Double Disk Steel Spur Slipper Kit for the Traxxas Tmaxx. FEATURES: Anodized blue slipper plates. Black steel spur gear and holder. Ball bearing replaces stock bushing. INCLUDES: One steel spur gear ring 72T. One spur gear holder Two blue slipper plates. Two slipper disks One ball bearing ( Three black screws One instruction sheet REQUIRES: Assembly on kit. SPECS: Overall thickness: 10mm (.394"") Overall diameter: 58.6 (2.307"") pjm 3/17/02 ir/kh