The large picture tube is a vacuum. If dropped or cracked, it can implode, sending glass shards flying.
These were the "brains" of the TV before the microchip. They controlled the flow of electrons to create sound and image. free tranny tv tube
To the modern eye, televisions are thin, lightweight slabs of glass and plastic. However, for over half a century, TVs were heavy, deep boxes powered by vacuum tubes. The large picture tube is a vacuum
If you are hunting for free TV tubes, safety is paramount. Vintage televisions are not like modern gadgets. it can implode