Marrying Strap
The Marring Strap was designed to free one hand allowing the other to hold onto a stair railing, ladder rung or hold a flashlight in a darken area.
Its purpose was to marry the irons (Axe and Pro Bar) to each other so the unit could be carried by one hand.
A further development allowed the arrangement to add the Tool unit making a complete forcible entry unit to be carried in one hand.