One pair of  8" foam surrounds suitable for the Prodigy Tower speaker including the 

                                                                                                                                        25177 etc.

Specifications are as follows.

                                                      OUTSIDE OF THE LIP   -  197mm

                                              OUTSIDE OF  THE BUMP     -  178mm

                                                   INSIDE OF  THE BUMP    -   150mm

                                                        INSIDE OF THE LIP     -   137mm

  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.