Universal 5x7 or 6x8 to 5.25&rdquo; And Tweeter PVC Component Speaker Adaptor 6mm 5x7 / 6x8 to 6.5 Speaker Adaptors ID / Speaker hole size = 5.625 Tweeter Hole = 1.5626" OD = 6.375 x 8.25" Thickness 6MM (.236)