Bought this on sale and it was unboxed so no mounting parts. The bolts fit perfectly. The other bolts for prior microwave looked same but thread count must have been different. If you force the old bolts you will ruin threads in microwave so if the old bolts dont go smoothly into new microwave get proper ones. need to test this before you mount new microwave.
the mounting bracket fit the existing tile opening perfectly. minor cabinet mod (chisel some of bottom of existing cabinets allowed the microwave to fit old tile opening. bracket was exact fit for my model. mounting bolt holes needed to be modified and that took the most time.