This is a heavy-duty hose and coupler for any standard grease gun. I like the locking mechanism on this coupler. I have had trouble in the past having the coupler disconnect and grease squirting all over the place. This coupler locks on so that won't happen. I got the kit with one coupler and hose, and two different needle fittings that connect onto the coupler. Not only can it inject grease into a zerk that you cannot get the coupler attached, but you can also use the needles to inject grease into crevices or other areas where you can't fit the coupler or there is no zerk, like door hinges, bearings, gears, rack and pinion, etc. The included zerk cleaner is a nice extra. You can run it with a hex bit in a drill, or just turn it manually on the zerk to clean the hole and outside of the fitting. What I would like with this kit though is a small bag that attaches to the hose to hold the needles and cleaner accessories. That would keep them handy where and when you need them.