Official Size & Weight Velocity Lacrosse Balls adhere to NCAA and NFHS standards. Our competition color balls (white, orange, yellow, and lime green) also adhere to NOCSAE specs and are SEI certified Lacrosse Sak Balls are the perfect practice ball for both indoors and outdoors so training can happen year-round in any weather. Playing on turf, grass, or wood gym floors you'll be glad they don't bounce and roll for miles like regular balls.