Odd.  In Ephesians 6, the helmet is salvation.  But in First Thessalonians 5.8:

“But since we belong to the day, let us be sober, having put on the breastplate of faith and love, and for a helmet the hope of salvation.”

Another oddity, I’m pretty sure the helmet in Ephesians 6 is for spreading salvation, but Thessalonians is easier to interpret as being saved.