A vessel in a modular magnetic storage system is set forth. The closing member 1 includes an elastic sealing element 3, and the closing member is constructed such that it biases in its inserted state the sealing element 3 in such a manner that it seals and secures the closing member 1 relative to the polygonal tube 8. A bubble wand having a handle in a different plane from the bubble forming member permits more efficient blowing of large bubbles. Interface portion is pivotable between open and closed positions and has a handle for receiving a force to move interface portion to open and closed positions.