Bought two of these, one for me and one for a buddy who needed to clear out some zerks.  If you have any grease zerks on any of your equipment, then you need one of these.  Notice I didn't say "might need" but rather "you need" one.  Easy to use, and it blasts the hard contaminated grease from the zerk as well as the greased joint.  Add new grease, and you're up and running.