They're not really for the backyard mechanic. They're more of an industrial, mining and other heavy equipment tool. They do move a lot of grease with almost no effort. Whitmore OilSafe rechargeable gun will be launched next month. It'll pump 85 grams per minute and can be used in combination with the OilSafe Grease Meter to measure output in grams, ounces and cc's. The Grease Meter is a great advantage if you calculate relubrication volume. It can be a great addition to an operation's grease management program.