S3, SB2, SM3 are disability swimming classifications used for categorising swimmers based on their level of disability. People in this class have decent arm and hand function, but no use of their trunk and legs. They have severe disabilities in all their limbs. Swimmers in this class have a variety of different disabilities including cerebral palsy and amputations. Events this class can participate in include 50m and 100m Freestyle, 200m Freestyle, 50m Backstroke, 50m Butterfly, 50m Breaststroke and 150m Individual Medley events. The class competes at the Paralympic Games.