VEVOR Core Drill Machine 305 MM 12 Inches Core Drill Rig Powerful Rugged Diamond Concrete Core Drill 110V 500 r/min Core Drill Rig Tool Wet Dry Concrete Brick Block Drilling 4800W 45 Degree Rotation

Hi, we have a VEVOR Core Drill Machine 305 MM 12 Inches Core Drill Rig Powerful Rugged Diamond Concrete Core Drill 110V 500 r/min Core Drill Rig Tool Wet Dry Concrete Brick Block Drilling 4800W 45 Degree Rotation. We are going to order an 8" drill bit for the machine but didn't know exactly what is the thread size of the bit or compatible one. Please advise and let us know the price. Thank you

What is the size of the arbor on this unit? Thread size on the arbor i guess is the question. That way a man can order the right size bits to fit it?