A City of Heroes question?

they wear down with leveling. it think its 3 levels difference. so when ur lvl 42, and ur buy lvl 45 enhancments, they are at max effectiveness. but when u hit lvl 45 they are at mid performance, and when u hit 48, they are at the lowest effectiveness. at lvl 49, they no longer do nething for ur powers. its not a time thing, its a lvl thing. and no, lvl 50++ never wear, because u cant go past 50.