欧美性zoo_夜夜摸日日操_大胆顶级欧美aaa级_经典av三级_成人视屏在线_一级 黄 色 片69

The machine is designed to grind four straight grooves of equal angle, equal width, equal depth and equal length on the grinding wheel surface. The operating cycle is controlled by automatic program, and all the slotting actions can be completed by pressing one button.