I have a wheel with a 7 speed dura ace cassette/freewheel. Where you would normally enter a cassette tool is a plastic cap with 2 holes for turning with a spanner wrench. It has an arrow pointing counterclockwise to open. This cap spins and spins forever with no effect.
How would this be removed? Is it possibly a uniglide (?) that you unscrew the small cog with 2 chain whips?
Thanks in advance