This is the Optional Nylon Top Gear for many Traxxas Vehicles. This top gear works on these Traxxas vehicles (as of the date of writing) in conjunction with the optional aluminum idler gear (TRAC7998). Bandit Rad 2 Rustler Stampede Nitro Street SRT Nitro Buggy Nitro Hawk Hawk 2 Blue Eagle LS/LSII FEATURES: Machined Nylon 22T Top Drive Gear INCLUDES: One Nylon Top Drive Gear COMMENTS: This gear MUST be used in conjunction with the aluminum idler gear because if you use the stock top gear you would have metal on metal which could cause interference. snew 07/10/00 ir/jl