TD Side Curtain Box Information
(Images are thumbnails, click to enlarge)

Top lip, front-to-back= 6in.        Inside Width=20 7/8 in.

Overall Depth=11 in (rear) 11 1/2 in. (front)

Inner Depth= 10 1/4 in.

Captive Nut Holes= 7/16 in. from edge

Wood screws =round head, 7/8" long