2 large glass valves originally from the Duga over the horizon radar system, each with Russian markings, the largest 28cm tall.

Duga (Russian: Дуга́, lit. 'arc' or 'curve') was an over-the-horizon radar (OTH) system utilized by the Soviet Union for missile defense as part of its early-warning radar network. It was operational from July 1976 to December 1989. The duga system consisted of two radars, one located near Chernobyl and Chernihiv in the Ukrainian SSR (present-day Ukraine) and the other in eastern Siberia (present-day Russia).

The duga system was a highly powerful radar, with a transmission capacity of over 10 MW, and it operated in the shortwave radio frequency range. Due to the intermittent nature of its emissions, characterized by sharp, repetitive tapping noises at a frequency of 10 Hz, it acquired the nickname "Russian Woodpecker" among shortwave listeners. This unpredictable frequency shifting often disrupted legitimate broadcasts, amateur radio operations, oceanic commercial aviation communications, and utility transmissions, leading to numerous complaints from many countries worldwide. The interference caused by the signal was significant enough that certain communications receivers started incorporating "Woodpecker Blankers" into their circuit designs to mitigate the impact.