Number of layers (specification):

Single layer 27 long

Single layer 40 long

Single layer 50 long

Single layer 60 long

Double layer 27 long

Double layer 40 long

Double layer 50 long

Double layer 60 long

Single layer 27 long (without cover)

Single layer 40 long (without cover)

Single layer 50 long (without cover)

Single layer 60 long (without cover)

Double layer 27 long (without cover)

Double layer 40 long (without cover)

Double layer 50 long (without cover)

Double layer 60 long (without cover)