HC-33 has auto demagnetize function where only action necessary is to aim and press button (for about 1-2 second) toward item to be demagnetized.
HC-31 does not have auto demagnetize function. The unit must be moved in a circular fashion (away from the object to) in order to be demagnetized.
Lead Time: 1-2 weeks NCNR
Note: HC-33 only available in 100V.