This periscope is heavy. ( 2,7 kg) If mounted on the stick, you need both hands to keep it steady. So it's no real trench periscope. It has a reticle. Made by R.&J.Beck London
R & J Beck was a renowned British optical company based in London. It was founded in 1843 by the nephews of J.J. Lister, Richard Beck (1827-1866) and Joseph Beck (1828-1891) who were in partnership with a famous instrument maker, James Smith (d. 1870). It started as Smith and Beck. In 1854 the company was renamed to Smith, Beck and Beck. After Smith's retirement in 1865 the company became R & J Beck. It produced a wide range of optical products: microscopes, telescopes, trench periscopes for army officers in the First World War, eye test glasses for opticians (optometer lenses), other optical equipment, and last not least camera lenses and even some cameras.
The height of the periscope from ocular to objective, is 37 cm.