manual undercarriage extension

例句：

1. 1. The manufacturerhas introduced a new manual undercarriage extension for the model Y.
   制造商为该型号的Y型车引入了新的手动式起落架延伸装置。
2. 2.This extension allows the vehicle to be lifted off the ground manually without needing a crane.
   这个延伸装置允许车辆在不需要起重机的情况下，手动将其抬起离地。
3. 3. The engineers worked tirelessly to ensure that the extension was functional and safe for all users.
   工程师们不懈努力，确保扩展装置对所有用户都是功能齐全且安全的。