perfect solution if you want to try a 12" speaker as opposed to a 10” quite a common upgrade 

This is 12-9/16” x 18-5/16”

And is baltic birch half inch ply with a baffle frame and a 5”x7” triangular logo mounting plate.

Unless specified the speaker cut out will be slap bang in the middle of the baffle

These come with 4x 2ba mounting bolts as opposed to 8 so you can use speakers that only have 4 mounting holes in there frames(fanes, Celestion’s etc)

Anything else just ask