This vintage Bell & Howell 6V6GT is a classic octal power tube from the 1950s. Known for its warm, rich tones, these tubes deliver a classic,  robust vintage sound prized in audio gear. 
 
Construction
Plates
- Commonly black plates.
Getters
- Varied, but often dual rectangular or flat bottom getters.
Internal Supports
- May include copper rods.
Glass
- Can have clear or smoked glass envelopes.
Type
- A low-power, beam tetrode vacuum tube (6V6GT designation).
Sound
- Delivers warm, round, and harmonically rich tones with deep lows and clear highs, making it a favorite for classic guitar amps and audio circuits. 
 
Why They're Sought After
Authentic Vintage Tone
- They produce the sound of vintage rock & roll and classic audio.
Quality Construction
- Made to high standards
 
In essence, a Bell & Howell 6V6GT is a collector's item, a reliable vintage component known for its specific tonal qualities in amplifiers and audio systems.