Create An Underwater Obstacle Courses with Swim-Through Pool Hoops These Swim-Through Hoops are the perfect underwater pool game for kids. Each set comes with four large swim-through hoops that are weighted on one side to keep them upright on the pool bottom. The hoops are three and a half feet in diameter, but can be adjusted to make them smaller for a more challenging course. Buy multiple sets to create longer courses along the entire pool bottom. Swim-Through Hoops assemble easily to create underwater obstacle courses Hoop diameter can be adjusted to create a more challenging course Set comes with 4 hoops; each hoop is 3.5 ft. in diameter Each hoop weighted with sand on one side to keep it upright on the pool bottom Fun, economical pool toy that provides hours of entertainment for young swimmers