One Jacket. Every Season. The AC400 Has You Covered!
Whether you’re grinding out a long run in the high country or smashing sprints on a frosty winter morning, the AC400 2-in-1 Windbreaker/Vest Combo is your all-conditions go-to!
Part of our UltraLite Running Series, this smart, season-proof design adapts to whatever the weather throws at you. Need warmth? Snap in the UL Running Puffer Vest. Heating up? Pack it into its own pocket bag and stash it in the windbreaker’s rear horizontal pocket — alongside your snacks and run essentials. Easy.
No more bulky cotton jumpers tied around your waist — just premium, ultra-lightweight nylon, an eco-friendly polyester fill (used in high-end snow gear), and months of thoughtful design poured into one sleek setup.
This isn’t just a jacket — it’s a game-changer for serious runners who demand function, flexibility, and style in every stride.
Note: Our windbreaker and vest designs are based on an athletic body shape. If you are leaning more towards a slightly looser fit or are between sizes, we suggest opting for one size bigger.
Please see sizing chart for guidelines.
2 reviews for 5am:RUN Mens AC400 2-in-1 Windbreaker/Vest
5.0
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Richard
Verified owner
Very comfortable, lightweight and keeps me warm on morning runs in cool weather. Brilliant product.
Very comfortable, lightweight and keeps me warm on morning runs in cool weather. Brilliant product.