Internally, one side of the box is parallel with, and the other inclined to, the lead of the rope, thus making the opening at one end wider than at the other.
Ngaphakathi, elinye icala lale bhokisi linxusene nelinye, elithambekele kulo, kwisikhokelo sentsontelo, nto leyo ebangela ukuvuleka ekugqibeleni kwelinye icala kube kukhulu kunelinye icala.