Molded from a special high-density polymer, these cassettes keep specimens safely submerged in liquid and are totally resistant to the chemical action of histological solvents. The efficient flow-through slots maximize fluid exchange and ensure proper drainage. The one-piece integral lid eliminates the need for separate steel lids. The snap-latch and hinge-lock design of the Unisette prevents early separation of base and lid and allows for one-hand operation. Lids can be opened and closed as often as necessary and always relock securely without danger of specimen loss. Large labeling areas are located on 2 sides of the cassettes. Anterior writing area is at a 35° angle.