12inch Sub flush mount adapter

I made this to Flush mount a 12 inch Sub into my box. I made a box to go into the back of my 72 VW Beetle and BC I am swapping out the rear bench for bucket seats I did not want ppl to lean back into the speakers. You need to print 4 of these to make a full circle. It fits a 12inch sub and I drilled out a 13 inch hole in my box. But if I was you I would print this and Test fit before you cut your holes.