Because these mechanisms are ceramic, they will grind salt, pepper and spices. A bottom-mounted locking grind adjustment knob eliminates the need for an adjustment knob on top of the mill, and the snap-in fitting does not require the use of metal fasteners. This lack of restrictions opens up a whole new world of design possibilities for woodturners. Complete illustrated mounting instructions are included, both have a 25-year manufacturer's warranty. This mechanism is manufactured for traditionally designed mills. However, as a result of the bottom-mounted locking grind adjustment knob, a metal adjustment knob at the top of the mill is not required. This gives you the freedom to create new and innovative stopper designs. This mechanism can be mounted using the built-in "catchers" or glued in place. The top is fixed into the stopper, which can be removed to refill the mill. Mill height can range from 5 to 12 inches.