A flame-retardant polyester artificial hair filaments is provided which comprises: 100 parts by weight of a thermoplastic polyester resin; 10-30 parts by weight of a polymeric phosphorus-based flame retardant; 0. The blender arm further includes a rotary shaft having a tool at the end opposite to the connection end. A uniaxially stretched phase difference film can be interposed between the polarizing plate and the liquid crystal cell, and a liquid crystal film fixed in nematic hybrid alignment can be interposed between the phase difference film and the liquid crystal cell. An exemplary method may generally include positioning a dusting tool driven by a drive motor in a predetermined dusting position such that the tool contacts or touches the component, and determining a first operating variable of the drive motor of the dusting tool when positioning the dusting tool in the predetermined dusting position. Additionally, the signal holder bracket may include one or more guards which prevent snow other debris from inadvertently removing the signal ball from the ring section.