• FHOM12 — 12mm Flex Head/Open End Combination Wrench. • FHOM15 — 15mm Flex Head/Open End Combination Wrench. Two Snap-on FHOM series Saltus-style flex head wrenches sold as a matched set. Open end on one side, 12-point pivoting socket end on the other — the flex head allows the socket end to swivel for use in tight, awkward spaces.