Durable A4 6mm Spine Bar Blue (Pack of 50) 2931/06Durable Spine Bar, these plastic spine bars are a versatile binding system for unpunched papers and documents in seconds. The unique contoured ends provide simple and easy insertion of all papers. The spine bar is 6mm in thickness meaning it can hold up to 60 sheets of A4 paper. Supplied in pack of 50 blue spine bars. Plastic spine bars for binding unpunched papers and documents in seconds Contoured ends provide simple and easy insertion of paper