Plastic  binding  combs,  USA-pitch  (21  holes  /  A4)

Dimens.                     sheets
                                                
====================                          
#    6                                       30
#    8                                       50
#10                                       70
#12                                       90
#14                                   110
#16                                   130
#19                                   150
#22                                   190
#25                                   220
#28                                   250
#32                                   280
#38                                   340
#45                                   410
#52                                   480

Main  advantage  is  that  if  the  document  is  continually  being  added  to  or  changed  plastic  
comb  can  be  opened  up  and  pages  can  be  changed  without  damage  to  document  or  loss  of  comb.  
Don’t  get  complete  360  degree  page  turn  as  spine  gets  in  the  way.  
Suitable  for  binding  documents  up  to  48  mm  (1  3/4”)  thick.