The Mark consists of a double-barreled pen or marker cap, one side of which is a completely- closed tube, and the other side of which is a partially-closed tube. The completely-closed tube side covers the marker tip, while the partially-closed tube side interlocks with the completely-closed side of other like caps, enabling a series of such caps to be linked together in an infinite chain. The broken lines show the position of the mark.
Trademark: 75896882
