Provided herein is a pneumatic carrier having a leak resistant cargo area where first and second mating shells form the carrier. To provide a leak resistant cargo area, the one embodiment of the carrier employs a flap-type sealing member. In one embodiment, a first engagement surface about a peripheral edge of a first of the shells includes a groove into which a base portion of a sealing member is disposed. A second portion of the sealing member forms a flap that extends upward and inward from the base portion. A second engagement surface of the second shell contacts this flap and compresses the flap toward the first engagement surface when the shells are in a closed position.