This 1/4 inch thick rubber underlay is incredible for raising hitting mats to the height of your turf in a built in system.  It doesn’t compress over time and will actually add better shock absorption through your mat.  It is not necessary to glue or tape this down, but you may do so if you wish. The max 1 piece width is 54 inches, but you only need to butt it up to the filler pieces.  No seaming involved, just cut it to fit and place as many pieces as it takes to cover your area.  Again, you may glue in if you like.