Only aluminum stoppers to have grippy notches allowing any size to be used back-to-back with any other size to make a completely solid placement whatever the width of the crack.

Ref: 57310, N°1 width 6-12mm
Ref: 57320, N°2 width 7-14mm
Ref: 57330, N°3 width 8-15mm
Ref: 57340, N°4 width 10-16mm
Ref: 57350, N°5 width 12-17mm
Ref: 57360, N°6 width 13-19mm
Ref: 57370, N°7 width 15-24mm
Ref: 57380, N°8 width 17-27mm
Ref: 57390, N°9 width 19-29mm