6.5 in Car Speaker Slotted Adapter Ring
A 9 mm spacer ring that adapts an aftermarket 6.5 in speaker to a factory door or dash opening, so you don't have to buy a brand-specific adapter or hack the sheet metal. It is 178 mm across with a 140 mm through-bore. It has eight radial slots, all covering a 148–164 mm bolt circle. Four 3.4 mm slots take #8 self-tapping screws for the speaker. The other four are 4.8 mm slots for #8 screws into the door, counterbored 8.6 mm wide and 3.5 mm deep so the screw heads sit flush under the speaker flange.
garage car-audio speaker adapter-ring