These are great for bird watching; however, the lense caps (4) are so loose that they do not stay on at all--but you need to use them so I get them on the best I can for storage & keep them in the bag.  I don't know what the answer is here as it would be awkward to have them attached by strings--they just need to fit better (perhaps testing them prior to selling them might be a good idea).  Do love the size & available adjustments so for the price, I'm a happy camper.