The ShurTrax All Weather Traction Aid safely and efficiently gives your automobile or SUV the extra weight it needs for added traction. Simply add up to 100 pounds of water to the dual-chambered vinyl ShurTrax unit (use additional units if more weight is needed). A siphon pump for easy, no spill filling and draining, and a universal fit garden hose connector are included. Unlike other items placed in the trunk for traction, ShurTrax isn't messy, thanks to several helpful design features: a continuous outer seal to eliminate split-able seams, a heavy vinyl exterior reinforced with woven nylon mesh, and brass grommets allowing the unit to be tied down/stabilized to decrease wear. ShurTrax is also made to freeze, and has been tested to minus 40 degrees without bursting..