Used left front caliper off of a '83 ZX750A1, this will fit: '83 EX305B1, '84-'85 ZX550A1/A2, '83-'85 ZX750A1/A2/A3, '84-'85 ZX750E1/E2 Turbo, and '83-'84 ZX110A1/A2. Not tested, good for rebuild or core.