Maybe it is the end piece on mine, but it seems to snap on the fitting just fine, but getting it off is a nightmare. I sometimes have to get pliers to yank it off.

 

I have a cheap Harbor Freight one. Works just fine, and I've had it for a couple of years.

I second the flexible hose thing - mine has a rigid nozzle, and it is a pain. Next time I'm at Harbor Freight, I'll pick up a cheapie with a flexible nozzle.

 

Prematex also sell preasurized grease in a 6 in. can with a flexible hose, kind of looks like fix-a-flat. it good to have kicking around in the travel tool box.

 

If you want a manually operated gun (which I prefer because it's not dependent on anything that might die, like batteries) there are two main types.
Pistol grip that has a max psi of about 6,000 that can be used with one hand and lever type that has a max psi of about 10,000 that requires two hands to use. Both of mine are lever type, one a 40 year old Plews and the other a Lincoln that's about 5 years old. The newer Lincoln actually seems to be of better quality.

Flexible vs rigid tube. On the pistol grip the flexible tube will work fine, however on the lever type if you have any flush style zerks you want a rigid tube.

 

 

That is awesome... too bad they didn't have one like that at AutoZone on Saturday when I was there...

 

Gotta go to one in a bad neighborhood and ask the warehouse guys in the back

 

You can buy just the flexible hose, its like a nickle, unscrew your rigid one, screw in the new one.