***** **********Best Quality Guranteed.
*****Binding Capacity: up to 50 sheets ( 80g 20lb) *****Length: 11.5 (36 Loops) *****100 per box, Color: Black. This spiral binding coil can not used with 4:1 pitch binding machine***** 3:1 Coil binding ring means per inch has 3 holes (This is very important distinguish 3:1 from 4:1 cause the things to be as different. 4:1 means per inch has 4 holes. They are used with different binding machine. )***** 3:1 pitch spiral binding coils great for reports and presentations with any 3:1 pitch coil binding machine.