This is an antique pair of Lane's Patent Steel Parlor Door Hangers circa 1891. These are marked Lane's Parlor Door Hangers with a patent date of April 22 1890, Aug 19 1891. The Lane's advertisement from 1891 describes their product as follows:

THE LANE PARLOR DOOR HANGER differs from others in several important respects. Among the chief points of superiority
may be noted: first. that it is made throughout of steel instead of cast iron, thus avoiding all danger or probability of breakage. How much annoyance and expense may be caused by an inaccessible defective hanger or track in a furnished house, those who have had such experience need not be told. The wheels run on a single Steel Track.
This Track is not liable to such derangement as swelling or shrinking, or springing out of shape from furnace heat or humid air,
but is thoroughly durable. The Track being secured to one partition instead of two, as in the case of the common double wood
tracks, is not subject to derangement from unequal settling of said partitions. The wheels of this Hanger are made with a centre of the very best sole-leather, the edge of which forms the rolling surface. This leather is a solid disc extending quite to the axle, and is firmly pressed and held between steel discs by means of steel nuts on a steel axle. The use of the leather in the wheel causes it to run with the noiselessness of a bicycle and the wear on the leather being a rolling one only, renders it practically indestructible. The extreme simplicity of this Hanger and Track makes its erection easy, and cost for labor very light; some carpenters say taking but a quarter of the time required for other kinds, and no cutting of doors; so that, if at a greater first cost, the expense when erected will generally be found much less than where the cheap grades of Hangers are used.
Avoidance of doors warping. We accomplish this by using one track only, the hanger suspended directly beneath it, and
the middle of the door fastened to the Hanger so that the whole weight of the door is suspended plumb from the Track, tending to keep it straight. and true. The principle is well-known to the horseman as applied to his whip. The axle of the hanger wheel does not run in a solid box, but is of the anti-friction type, and most people now recognize the great superiority of anti friction Hangers over the old style, noisy, hard running kind with fixed bearings. Each Hanger may be adjusted independently of the other by use use of a screwdriver and without derangement of any part. The Stop we make of steel, and place at the rear of the door and midway; the door thus will strike square as it should do. We make the Stop on the gravity principle, and if either door should need to be run out in the passage way, a knife blade may be inserted at the side and rear edge of the door, turning the Stop one quarter way around, when the door will be free to pass out.