Contrary to what MinnFlyer said Tru-Turn does claim to balance its spinners and I have yet to buy one that was not balanced although I have not bought a great deal of them, 3 or 4. They also make W slotted spinners and I seem to remember another Tru-Turn spinner I bought with what was called a 120 slot, I bought that one when I was having problems fitting a 91. 4 stroke on an AT6. So they do indeed make larger slotted spinners but I am not sure what size and styles are available.