Saves time and eliminates spills and mess. It is improved. Includes threaded cap and adapter for newer GM threaded style radiator openings. The spill-free funnel eliminates trapped air pockets which usually cause erratic cooling system and heater performance. It controls the proper amount of coolant entering system and enables unattended filling of the cooling system. The funnel eliminates squeaky belts caused by coolant overflow and protects the environment. Four adapters fit most domestic and import cars and light trucks. Angled neck allows use on radiator caps that are placed at an angle. GM threaded cap is found on '04-'07 Grand Prix, '06-'07 Buick, '04-'07 S10 Blazer, Canyon, Colorado, SSR, Trailblazer and Olds Bravada. Also found on '07 GMC Acadia, '06-'07 Hummer, Torrent, Equinox and Tahoe.