Durable Spine Bars, WhiteDURABLE's plastic spine bars are a versatile binding system for unpunched papers. The uniquely designed contoured ends provide simple and easy insertion of all papers. Durable Spine Bars White Available sizes 3mm Capacity 1 30 A4 Sheets, 13 x 297 mm 100 box 6mm Capacity 1 60 A4 Sheets, 13 x 297 mm 100 box 9mm Capacity 50 90 A4 Sheets, 15 x 297 mm 25 box