The invention relates to stable compositions for providing PVC with fungicidal properties. The exfoliating agent applied in the present invention has the formula:wherein n=1 to 5 and R is a polyoxypropylene group, poly group, polyoxybutylene group, or polyoxyethylene group. The skin pressure plate is provided with two spaced apart needle guides. The tapered portion has a width that is gradually reduced toward the output end, and the aperture is formed in a C-shape by a ridge formed on an inner surface of the metal body. A shift member axially presses on the tails of the pawls to disengage the heads of the pawls from the driven member. The board has a first board surface, a second board surface and a circuit.