thats the terms of taking to pieces WI Eno Trials freewheel 18t there are 6 pawls(3 short and 3 long) on the main screw body, ratchet 18t steel cog and sealed bearing if smth isnt clear up there just ask me in short: you need freewheel when you are using fixed rear hub they differ by their free run most popular: acs, eno, tensile and try all