Description: 【Part Number】: 137-4823 121-9180 115-1992, please check the listing pictures and part numbers carefully to ensure they are correct 【Metal Construction】: Crafted from metal materials for enhanced durability and longevity. This sturdy construction ensures that the transmission can withstand regular use in demanding mowing conditions 【Compact Packaging Dimensions】: The product comes in compact packaging with dimensions of approximately 57cmx12cmx13 cm 【Single Unit Package】: Each purchase includes 1 complete transmission assembly unit ready for installation on lawnmowers 【Application】: Lawnmower transmission is ideal for both professional landscapers and DIY enthusiasts looking to maintain their equipment efficiently, Upgrade your lawnmower's performance with this reliable Transmission Assembly Specification: Material: Metal Color: Black for 20330 for 20330C for 20331 for 20331C for 20339 for 20339C for 20350 for 20351 for 20353 for 20370 for 20371 for 20377 for 20378 for 20954 for 20960 Size Chart: Package Size 57cmx12cmx13cm/22.44inchx4.72inchx5.12inch Package Includes: 1 Transmission Assembly Note: Please allow slightly errors 1-2cm/0.39-0.79inch differences due to manual measurement.