Image Item No. Description  18590  Technic, Gear 8 Tooth with Pin Holes and Ninjago Flywheel Socket - Short Shaft Catalog: Parts: Technic, Gear  18940  Technic, Gear Rack 1 x 14 x 2 Housing Catalog: Parts: Technic, Gear  18942  Technic, Gear Rack 1 x 14 x 2 with Axle and Pin Holes Catalog: Parts: Technic, Gear