Canon and third-party manufacturers do not offer to me a satisfying solution. That’s why I thought about and I researched how to protect the front lens during transport without having to use the original lens cap. In my local hardware store, I found something and came up with the idea of using a canal system cap (160x4). The cap fits perfectly on the lens when the lens hood is not attached. Because the cap was a little too long, I used a metal saw to reduce the height of the cap. Then I attached a handle to the front of the cap (riveted polyester strap), and on the inside of the cap I stuck a trimmed piece of insulating mat. Since then, I have a suitable lens cap that saves space, provided I do not want to use the lens hood.