... is hollow, but elastic.CE Wire Markers: Material of cable marker:made from PVC, oil and erosion control, heat resisting up ... .Approx wire(SQ)Approx wire(mm)MarkersLength of each rollCable Marker EC-00.75~1.52.0~3.20~9 A ... ~Z +-/ \1000pcsCable Marker EC-10.75~3.53.0~4.2500pcsCable Marker EC-23.5~8.03.6 ... ~7.4500pcsCable Marker EC-35.2~10.05.2 ...