Bumper for wardrobe doors.

Johnson hardware calls this a snubber.  
Rubber stop mounts into track channel.
Prevents over travel of doors.
Accommodates 5/8 inch track.

Color: Mill
Length: 7/8-inch
Material: Rubber
Width: 3/4-inch

Priced and sold each.

Note: These come in 2 sizes: 3/4" & 1" track.
It fits at least track 2610F096, 96, and probably others.