When the bellows part twists it easily peels off and it will split. There is a hole from there, it will not become a negative pressure and it will be impossible to suck dust. The bellows part is a repetition of twisting and bending certainly when doing various work. You should make it more robust! Since adhesion is too weak, it is necessary to review the bonding method used when manufacturing the product! Even if it becomes expensive, I will purchase it if it is neat article.