I bought this bag to carry an external DVD drive for my laptop. The case is strong enough to provide crush protection and the DVD drive fits in without much slack, reducing the likelihood of internal shock damage if the case is dropped. One side of the open clam-shell design has an elastic band to keep the carried item in place, while the other side has mesh to carry smaller items (in this case, a connecting cord for a DVD device) . I found there was plenty of room to carry other items and the micro mouse I have fits in perfectly and is snug enough to provide extra support for the DVD device when the clamshell case is closed. I highly recommend it.