A latch mechanism is configured to secure two containers together and includes a housing, a latch, a main body and a primary hook. The latch is rotatably engaged to the housing and movable between a first position, wherein it can secure a second container to the housing, and a second position, wherein it cannot secure a second container to the housing. A stopper is slidably engaged to the latch and includes a locking surface and holding surface. A stopper bias biases the stopper toward an upper position such that when the latch is in its first position, the locking surface and primary hook create a negative space which receives and secures the second container to the housing, and when the latch is in its second position, the holding surface is configured to engage a second container and prevent the latch from rotating back to its first position.