Black Friday: lifetime access is on a special offer in the app, until November 30. Black Friday: special offer on lifetime access, until November 30. Download
이 기계는 역전장치를 사용하여 방향을 바꿉니다.i gigyeneun yeokjeonjangchireul sayonghayeo banghyang-eul bakkubnida.This machine uses a reverse mechanism to change direction.