I have a #1 tool and it does not fit either which I expect. I looked at a webpage( SB) that described cassette/FW, I have the hub that is larger towards the end, I have the #1 and # 5 tools and neither works. My #1 fits nicely into a fw I have. The #5 barely engages either lockring, if I just take the HG50 ring off the cassette it barely fits.