154-0699-00
The Tektronix 154-0699 (-00, -50) is a directly heated cathode-ray tube for miniature scopes.
Standard phosphor is P31. The (non-illuminated internal) graticule has 6 × 10 divisions of 0.203" (5.16 mm) each.
Typical acceleration is -1 kV at the cathode, no post-acceleration.