I would rate this as probably the worst item I have purchased ! If you rotate the lever clockwise, the knob unscrews and drops off. The shutter over the bean hopper was extrememly stiff and difficult to move. And to grind enough coffee for two mugs is equivalent to a good work out in the gym I reckon !! Electric burr grinders are now so reasonably priced I would avoid this manual one like the plague ! I have given it one star purely because at least it looks nice !