This is the HO Scale Curved Steel Girder Bridge Kit (Single Track) from Kibri.
Kit. Excluding piers. Suitable for all common track systems. Only single track construction is possible. Includes 2 slanted extension parts. Dimensions: L 30 40 x W 7 x H 3 cm. Radius = 357 360 mm, 45°. Road height: 2 cm. Level of difficulty: 2 (advanced learner)