Suntour stuff isn"t easy to come by any more, but it was well made enough that there"s still plenty kicking around. If you"re one of the lucky ones who still has a Suntour bike, then you"ll need the Park Tools FR-2 to remove the 2-notch lockring on your cassette. Fits older Sun Tour two notch freewheels Two notches are approximately 25mm across measured outside to outside Not recommended for Sun Tour four to six notch freewheels 1" base fits wrench or bench vise