Digital Holster 50 plastic "Pop Down" Expansion Feature Allows for two Different Vertical Heights: A horizontal zipper is located on the very bottom of the bag; when unzipped, the bag extends down vertically to allow for different-sized lenses, or one lens with the hood in position, ready to shoot Shoulder Strap: A mid-weight, no-slip shoulder strap is provided to carry the bag while preventing it from sliding off of your shoulder "Rotate or Lock": The back of the bag incorporates the Think Tank Photo "Rotate or Lock" mechanism, which allows you either to rotate the entire bag on the Pro Speed Belt or to lock it into position with the plastic tab. Or, it can be attached to a regular belt with the hook & loop attachment system When wearing the Digital Holster on the Pro Speed Belt make sure to rotate the bag regularly along the belt during the day to shift the weight and achieve maximum comfort. You can also use the shoulder strap to help distribute the weight Seam-sealed Raincover: A pocket on the inside holds a seam-sealed raincover. It is also completely removable from the bag for convenience. The Digital Holsters adjust to two different vertical lengths so seam-sealed raincover can also be adjusted to two different lengths