The 302's belt loop is permanently sewn into the case at the top and bottom. It runs the entire length of the case, and might accommodate slipping through backpack hip belt. You'll have to undo your belt each time you want to wear or remove it.

The 4390's belt loop attaches to the bottom of the case with a single snap button (no supplemental velcro). It is made from thick nylon webbing but is shorter in overall height compared to the 302. The snap button makes it easier to get on and off without undoing your belt, but it's also less secure (especially with no supplemental velcro).