It is used on all these bikes
CB400F A MOTORCYCLE, JPN, VIN# CB400F-1000006 TO CB400F-1038492
CB400F A (76) MOTORCYCLE, JPN, VIN# CB400F-2000001 TO CB400F-2008280
CB400F A (77) MOTORCYCLE, JPN, VIN# CB400F-2100001 TO CB400F-2104166
CB500T A MOTORCYCLE, JPN, VIN# CB500T-1000001
CB500T A (76) MOTORCYCLE, JPN, VIN# CB500T-2000001
CB550F A MOTORCYCLE, JPN, VIN# CB550F-1109886
CB550F A (76) MOTORCYCLE, JPN, VIN# CB550F-2000003 TO CB550F-2010866
CB550F A (77) MOTORCYCLE, JPN, VIN# CB550F-2100001 TO CB550F-2114871
CB550K A (77) MOTORCYCLE, JPN, VIN# CB550K-2000007 TO CB550K-2015308
CB550K A (78) MOTORCYCLE, JPN, VIN# CB550K-2100001 TO CB550K-2122082
CB750A A (76) MOTORCYCLE, JPN, VIN# CB750A-7000001 TO CB750A-7007331
CB750F A MOTORCYCLE, JPN, VIN# CB750F-1000002 TO CB750F-1015054
CB750F A (76) MOTORCYCLE, JPN, VIN# CB750F-2000003 TO CB750F-2022317
Here's one if you want stock style
http://www.partsnmore.com/parts/honda/cb550/?filters%5Bcategory%5D=electrical&filters%5Bmodel%5D=cb550f&filters%5Bfitting%5D=customhttp://www.vintagecb750.com/products/5/45/64/wire-terminals-couplers-fuse-boxes-fusesDavid Silver Spares restores 400F and has MANY new and reproduction parts for your bike just not the fuse holder.