Bolt center to center is 15.250" on this gasket and gasket is .125" thick. Opening in gasket is 15.125" x 4.375".
This gasket is designed two injector gaskets sandwiching a screen as where other versions use a single injector gasket with the screen stapled to the gasket making the screen susceptible to coming loose and you know what is next, into the blower!!!!!!!!!!! Don't take chances with inferior gaskets get the good one.