One pair of  4" foam surrounds suitable for the Fosters speaker , including the                                                                                                                                                 9162C ,     C100134A9010 etc.

Specifications are as follows.

                                                      OUTSIDE OF THE LIP     -  98 mm

                                                OUTSIDE OF  THE BUMP     -  89 mm

                                                    INSIDE OF  THE BUMP     -  73 mm

                                                         INSIDE OF THE LIP      -  64 mm.

  THE ADHESIVE USED INTHE INDUSTRY TO GLUE FOAM SURROUNDS IS OF THE ACETATE FAMILY.IT IS SOLD COMMERCIALLY AS EITHER PVA ( WOOD GLUE ) OR AS EVA ( CRAFT GLUE ). IN THE UNITED STATES IT IS SOLD  COMMERCIALLY  AS ELMERS GLUE.