Won"t scratch, chip, peel or discolor. 19-ring plastic spines bind 11 x 8-1/2 sheets. Compatible with GBC and other plastic comb binding machines. To select correct diameter, measure thickness of material (including covers), add 1/8". Communicate your ideas with professional polish. 19-ring plastic spines won"t scratch, chip, peel or discolor. Bind 11 x 8 1/2 documents. Editing capability with a machine. Compatible with GBC and other plastic comb binding machines. To select correct diameter, measure thickness of material (including covers) and add 1/8". Global Product Type: Binding Spines-Comb; Binding Spine Type: Comb; Sheet Capacity: 125; Spine Diameter: 5/8 in.