Image Item No. Description  32185  Technic, Gear Rack 1 x 14 with Holes Catalog: Parts: Technic, Gear  742  Technic, Gear Samsonite 21 Tooth Catalog: Parts: Technic, Gear  743  Technic, Gear Samsonite 35 Tooth Catalog: Parts: Technic, Gear  744  Technic, Gear Samsonite 42 Tooth Catalog: Parts: Technic, Gear  768  Technic, Gearbox 2 x 4 x 3 Catalog: Parts: Technic, Gear  6588  Technic, Gearbox 2 x 4 x 3 1/3 Catalog: Parts: Technic, Gear  6588  Technic, Gearbox 2 x 4 x 3 1/3 Catalog: Parts: Technic, Gear