anyone use medella bottles?

Have just bought medella teats to put on the bottles i have with my breast pump, when they arrived they were just teats with no caps to go over the top. I have lids on the bottles, and the teat fits into one of these but there is no cap for over the top of the teat. Which will mean having to find a sterile container to store the teats in whilst on the move and then them having to be slotted into the lid when needed. I can't find these online anywhere - is there anyway round it? x