The nice designed wire book binding machine will help you to create professional proposals, use double sprial wire binding your documents can lay flat 360 degree. It's one of the best book binding solution for your all book binding. spiral wire book binding machine OBWY970 specification: Max. paper punching ability: 20pages (80g paper), PVC cover 6-pages; Max. paper binding ability: 120(14.3mm wire); Margin adjustable range: 2. 5mm-6. 5mm; Number of paper punching holes: 40 holes, adjustive all of pull-push pins (3: 1"); Metal body; N.W:17.5kgs We have 3:1 pitch sprial wire binding machine for smaller books, 2:1 pitch double loop wire binding machine for larger books and a combination wire binding machines. There's also double loop wire binding machines that can do plastic comb binding. You can choose the manual twin loop wire binding machine or electric double sprial wire-o binding machine or double loop wire closers from OBINDER.