The Jet Swet system allows you to swet/solder on a copper line without draining the entire water system. (I really wish I’d heard about this before I re-routed all the copper lines in my basement.) Just insert the Jet Swet through the valve or pipe and compress the Jet Swet gasket to instantly shut off the water. It’ll hold back up to 65 pounds of water pressure — plenty if you’re in an established neighborhood. (Be careful if you’re in a new-build; they often boost the pressure in anticipation of the development filling up later.)
The 6100 kit comes with six tools in sizes 1/2, 3/4, 1, 1-1/4, 1-1/2, and 2″, all housed in a plastic carrying case. And Accent Shopping carries them right now for $225.