they have a specific line-up (OTP) to make production faster and easier, that how they were able to keep the price low and production quickly, as they don't cut the tube to your specification, they were already cut, all they have left is to put it together and paint it.
they have a specific line-up (OTP) to make production faster and easier, that how they were able to keep the price low and production quickly, as they don't cut the tube to your specification, they were already cut, all they have left is to put it together and paint it.