Bearing type: 4 Bearing, Angular contact bearings, P4 grade, 2x7005C P4 DT and 2x7003C P4 Power Interface: optional GX16 air , there are marked 1234, 123 were connected to the inverter power supply (U, V, W), 4 connected inverter ground. Bearing is P4 grade, 2x7005C P4 DT, 2x7003C P4 DT, increase spindle life. High-speed electric main bearings used in all C class high-speed angular contact ball bearings, axial pre-load feature, improved support stiffness and live spindle grinding accuracy under high-speed rotation. Main Application: engrave for wood, bamboo, normal PCB, PVC, PMMA, plastic, duotone board(ABS)and etc nonmetal, also can engrave on gold, silver, copper, aluminium, Pb etc soft metal surface working., Manufacturer: MOOILKO