Many tests involve an array of small reagent containers, vials and dropper bottles. These polyethylene bottle stations help keep materials organized and upright on the lab bench. Each station has one hole size. The small unit accommodates 11 bottles up to a 1.5cm diameter. The mid-sized unit holds six bottles up to 2.3cm and the large unit has four positions for containers up to 3cm in diameter. The stations may be purchased and used separately. The step rack holds any three stations to keep as many as 33 bottles properly arranged. The step rack set includes a step rack with one each of the three bottle stations. For different combinations of bottle stations, order components separately.