double rims are rims hav two rims on them, 1 rim is on top of another one...so the rims is thicker....they usually hav dem at recreational out door courts here in canada....... also there hella bouncy so if u miss a shot it bounces off farther than ur regular rims......i still hav trouble wit dem rims there just sumtin bought dem that throws u off...but i hav a friend who lives real close to a double rim court and he says it really helps ur shot or confidence in shootin..... all i can say is just practice on shootin on dose sorta rims more...