Woolwax 4 Spray Can Undercoating Kit. Black. If you don't have a compressor, you can still treat your vehicle with Woolwax . This offer is for a Woolwax aerosol spray can undercoating kit. This includes a conversion trigger made to fit the Woolwax 12 oz can, that turns the spray can into a spray gun. Also included in a 24" extension wand with a 360° nozzle to get inside the doors and tight spots. This kit is especially good for people that may not live in the heavy snow and ice areas, but still want to protect their vehicles, boat trailers, outdoor equipment and more. The conversion kit can be used with or without the extension wand. Woolwax is formulated with more woolgrease than any competitive brand. Woolwax is thicker and more resistant to wash-off than any other lanolin film product.. Woolwax is a wet coating and does not dry.