S4, SB3, SM4 are para-swimming classifications used for categorising swimmers based on their level of disability. Swimmers in this class have coordination problems affecting all four of their limbs, or have movement in their arms, some trunk function and no leg function. 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.