#1 are press-in grease fittings, 2 per door (1 per hinge). Be careful mine were screw-in and instantly broke when I tried to remove them because they were plugged and wouldn't accept grease. I had to drill them out and press in the ones you call #1. By the way, if you order the original screw-in type by part number from Mercedes, you will still get the press-in version and have to rework your door hinges for them to work - don't bother to ask me how I know.
Tom Kizer