This plate goes behind/inside the transom and is what your motor mount bolts will attach to. This is a much simpler and more efficient way of mounting your engine instead of using individual nuts and washers. The holes are tapped for 6-32 bolts. This plate distributed the clamping force across a much larger area so you don’t deform the transom area while fighting the motor mount. It also eliminates the need to have wrench/pliers access in the transom when making adjustments to the engine mount. This bolt pattern is ONLY for the OS XM engine mount. Made in the USA from billet 6061 aluminum.