*12 inch Max Drilling Diameter: Our core drilling machine generates extreme power because of its 4800W copper motor. Maximum Speed: 500RPM. Maximum Coring Diameter: 12""/305 mm. More importantly, the 4.25""/108 mm core bit in the picture is included. *Durable Construction: As the machine will work upside down, so water would unavoidable flow on to the drill machine. In this case, our drilling rig has a rustproof steel forged output shaft and waterproof copper water inlet for a long-lasting water supply. *Thoughtful Security Design: We also provide overload protection system and an upgraded cooling system. They are designed for avoiding burn-in and prolonging the service lifespan of the drilling press machine. *Ergonomic Handle & Stable Base: It features an ergonomic handle and 45-degree rotatable large base support for effortless drilling or getting oblique holes. The aluminum guide rail makes the drill rig's movement more smooth and accurate. Two casters for easy transport. *Wide Application: The wet diamond core drilling rig can be widely used in drilling reinforced concrete, red brick, marble, and other materials. It is perfect for installing air conditioners, pipes, stair railings, and repairing highways, etc. *Specifications Max Drilling Diameter: 305mm (12"") Rated Input Power: 4800W Rated Voltage: 220V Rated Frequency: 50Hz Speed: 500 r/min *Pakcage Content 1 x Diamond Drilling Machine 1 x Diamond Bit 1 x Manual 1 x Accessory Set (1 x 5 hex socket wrench, 1 x 6 hex socket wrench, 1 x 17-19 offset spanner, 1 x 200-type trap, 1 x Internal expansion bolt, 1 gasket, 1 x set of water pipe + joint, 1 x leakage protector)