An anti-skid device for use in cooperation with a vehicle wheel for positioning a traction member beneath the vehicle wheel includes a frame assembly constructed and arranged to be attached to the vehicle, a swing arm pivotally connected to the frame, and an electric, linear actuator having an extendable shaft. The toner is also excellent in the stability in long-term of the chargeability and capable of forming images maintaining high image quality. High contrast interfaces are defined between the semiconductor and the insulator. A length from an edge of the alignment tab to the second end of the first rectangular section adjacent the tapered section is approximately equal to a minimum arm circumference for the blood pressure cuff. The body 18 has an inner surface 26 with a plurality of radial grooves 28 spaced apart along the length of the body 18 in the form of groove clusters 30.