Pit Zips
Jargon
Definition
What the hell is a pit zip? The name can be a bit confusing but it makes more sense when you say armpit zip which can be found in outdoor jackets, commonly in higher end rain jackets.
As the term implies this is a zip that starts in the sleeve above the armpit and goes part way down the body of the jacket. When the zip is opened, partially or fully, it allows air movement through the jacket, which is particularly helpful when you are on the move. This air movement minimises heat build up that may cause you to sweat, particularly in hot and humid weather.
The wider you open the zip the more the air can flow through the jacket and unless it’s raining heavily, a well designed jacket will limit water entry. If the rain becomes torrential you can close the zip to minimise any chance of water entering the inside of the jacket.
Not all jackets have pit zips but having them provides a degree of versatility for heat management.
Front view of my rain jacket
View of under arm with the pit zip closed
View of under arm with the pit zip open