15mm Fieldstone rock walls. Straight wall 4" 6" Sections up to 3 feet. UTW501: : 3 feet of field stone wall 15mm short : 15mm Fieldstone rock walls. Straight wall 4" Sections up to 3 feet. UTW502: : 4 feet of field stone wall 15mm long pack: 15mm Fieldstone rock walls. Straight wall 4" 6" Sections up to 4 feet. UTW503: : 4 Feet of Field Stone Wall 15 .