Maker: Sheaffer.
This page refers to the Balance model using this name.
The Vigilant is the military clip equivalent of the Sovereign; slender, full-length body with a Lifetime point.
Production Run: 1940 – c. 1942 (I have a suspicion without supporting data that it would have been kept on until the end of the war).
Cost When New: $8.75 (for modern value, try this calculator).
Size: 13.2 cm long capped, 15.1 cm posted, 11.5 cm uncapped.
Point: 14k gold with platinum mask.
Body: Celluloid.
Filler: Lever, capacity approx. 1.0 ml or vacuum filler, capacity approx. 1.5 ml.

Sheaffer Vigilant, vacuum filler, gold pearl striated. Note the placement of the white dot; it can’t possibly serve as advertising from there.

Sheaffer Vigilant, black vacuum-filler. With the cap in profile, one has a better sense of the literally over-the-top nature of the military clip.
If you are relying on the preceding information to win a bet or impress a teacher, you should read the site’s scholarly caveat. Remember, this is the internet, and it’s full of bad information.