Each carrier accommodates up to four standard microplates, one Beckman Coulter deep-well, one square well plate, or one 96-tube rack. Provides the following g-forces for cellular assays and quick microplate spins: Allegra X-12 is 2,890 x g (3,750 rpm). Allegra X-14 is 3,283 x g (4,000 rpm). Allegra X-15R is 4,460 x g (4,450 rpm). For use with the SX4750 and SX4750A. Each Microplate Carrier Assembly includes carriages and rubber pads (Set of 2). Covers sold separately.