-Can be crimped to any rectangular wire from .016x.025 allowing you to secure an anchor for any auxiliary attachment. -Ultimate Hooks Crimp to Rectangular wire from .016x.022 to .019 x.025. -Placement is easy… Place the Ultimate Hook on the arch wire using Hook crimping plier or a hard wire cutter and apply pressure. If placement is made with a hard wire cutter apply pressure on the mesial and distal side of the hook. Note: Short hooks must be placed with a hard wire cutter. **For further product information, please contact Chat Support**