The house flag of the India Rubber Gutta Percha and Telegraph Works Co Ltd, London (Silvertown Telegraph Co). The flag is made of wool bunting, machine sewn with design details painted onto the fabric; the hoist is made of linen. A rope and wooden toggle is attached.

A rectangular red flag with a pale blue border. A white telegraph cable runs across the red field top left to bottom right. In the lower right half of the field two clasped hand proper, in the upper right half - a dove with an olive branch.

The house flag of the Silvertown Telegraph Works, a subsidiary of the India Rubber, Gutta Percha and Telegraph Works Company. The parent company was founded in 1852 by Samuel Winkworth Silver, who gave his name to the district on the north bank of the Thames. The company stopped making telegraph equipment around 1930, and eventually became part of BTR Industries (formerly the British Tyre and Rubber Company). This later merged with Siebe to become Invensys.