This Victorian flat stair bracket was made by the Russell & Erwin Manufacturing Co. The number 3002 also appears on the back.  It measures 2 5/8" wide at the center, 5 3/4" long, and weighs 11.29 oz.  The three-hole end mounts to the wall and the other end attaches to the underside of the handrail.

The back is marked RE Co., USA, 3002.  Nice, original condition.

Please see the images provided, as they're part of the description.