G4030
περικεφαλαία
helmet
περι-κεφαλαία, -ας, ἡ [in LXX for כּוֹבַע, קוֹבַע ;] a helmet: figuratively, 1Th.5:8; with genitive explic., π. τ. σωτηρίου, Eph.6:17 (cf. Isa.59:17).† (AS)
The KJV translates G4030 in the following manner:
helmet (4x)
Full Thayer's lexicon entry
περικεφαλαία — perikephalaía
περικεφαλαία, περικεφαλαίας, ἡ (περί and κεφαλή), a helmet: 1Th 5:8; τοῦ σωτηρίου (from Isa 59:17), i. e. dropping the figure, the protection of soul which consists in (the hope of) salvation, Eph 6:17. (Polybius; the Sept. for כּובַע.)
2 occurrences
Ephesians (1), I Thessalonians (1)