Two levels with five spaces each for culture bottles of 108 – 121 mm Ø and a length of 290 mm. Soft rubber roller for better grip and to avoid vibrations. The roller is moved by a transmission-drive belt construcgion. Powerful direct current engine for rolling speeds of 0.1 to 3.8 rpm (for culture bottles 110 mm Ø). Rolling speed adjustable variably. An additional roller deck increases the capacity to 15 culture bottles.