This EasyDip system is a handy tool for labs that do slide staining. Each set includes a square staining jar and a vertical rack that holds up to 12 microscope slides. You just dip the whole rack into the jar of stain or other solutions, which processes multiple slides at once very evenly. The square jar design is efficient and helps prevent tipping. This listing is for a pack of 6 complete systems (6 jars and 6 racks). The jar dimensions are roughly 4.4 inches in some dimensions (specifics can vary). It's a simple, reliable, and reusable system for histology, cytology, or any lab work requiring consistent slide staining. Saves time and reagent compared to staining slides individually.