The PB-4100 Hard Case "Shoulder Bag" is a lightweight, waterproof, unbreakable case designed to be hand-carried or slung over your shoulder with an optional HB-15 shoulder strap. The case can be used to carry audio, photo or video equipment and accessories. It meets ATA 300 specifications for shipping cases. The hard resin shells are virtually unbreakable and the interior rubber O-ring keeps the case air and watertight. The case has an air pressure release valve. It is carried by a super-soft rigid grip handle.