Optima units are designed to be kept filled with water. However at times it is neccessary to store the tank dry. Keeping the tank dry for long periods of time can result in a slight, and temporary, distortion of the wash dividers. This does not impare functionality but at times it can make print holders difficult to get into the slot.
The wash divider comb fits all wash capable Optimas and allows the tank to be stored dry with the wash dividers remaining straight. If you are buying a full set of wash dividers you will not need to buy a comb as you will receive a comb for free.