Toolzone 6 piece bi hexagonal ring spanner set set of 6 double ended bi hexagonal ring spanners each spanner has a different metric sized ring at each end drop forged carbon steel heat treated chrome plated for added durability all contained in a plastic holder for storage when not in use sizes 6mm x 7mm 8mm x 9mm 10mm x 11mm 12mm x 13mm 14mm x 15mm 16mm x 17mm colour silver