The Clear Crank Top four piece 3.0" grinder is Kannastor's flagship product and features extra deep storage chamber so you can grind and store more at one time. The clear polished lucite grinder top with aluminum teeth offers a perfect window to watch the powerful grinder do its work. You’ll know right away when the job is done. This grinder has added security and all connections are threaded to keep your herbs intact and comes with a removable screen feature that is held in place with a tension ring. For $30 more, you can grind your herbs till the cows come home. And to top it all off grinders come with a one year limited warranty.