Multiple Slip Joint Spanner For metric and imperial nuts and screws with widths across flats from 10 to 32 mm (3/8 up to 1 1/4), self-locking from 17 mm: no slipping on the workpiece. Zero-backlash gripping of metric or imperial hexagonal headed screws, no rounding of bolt heads. Reliable and tight gripping of rounded, rusty, or thick coated bolts and s