the OMM Core Vest

the OMM Core Vest

See our entire range from the OMM here!

The OMM Core Vest is an extremely lightweight and highly breathable insulation vest , developed for active use in the mountains where traditional insulation often gets too warm. It is part of OMM's innovative Core series , which is built entirely around PrimaLoft® Active , an insulating material that combines fleece-like warmth with more than half the weight reduction compared to classic fleece.

The vest is constructed from synthetic insulation fibers (plumes) woven directly through an open mesh material . This structure creates very high loft and effective thermal insulation , while the material's almost total air permeability means that excess heat is quickly ventilated away. The result is a garment that can be worn during high activity without having to be removed , by instead regulating the temperature with a thin shell on top.

When combined with a lightweight windbreaker – such as OMM’s Sonic Windproof – the Core Vest becomes a surprisingly effective insulation layer with unbeatable warmth-to-weight performance. When you get too warm, simply open or remove the shell, while the Core Vest can stay on and continue to insulate when needed. This makes it a true “valley-to-summit” garment , suited for fast rides where terrain, weather and intensity change.

Core Vest works equally well wet or dry . PrimaLoft® Active insulates even in moisture and has very good moisture transport , which means that the garment dries quickly and does not feel cold against the skin after sweaty climbs or rainy sessions. It can be worn as a very warm first layer in extreme cold , or as an insulating mid-layer over a thin base layer.

Weighing only about 72 grams, the Core Vest is one of the lightest ways you can add significant warmth around the core of your torso , without significantly affecting pack weight or freedom of movement.

Features & Benefits

PrimaLoft® Active 75 g/m² – extreme warmth in an ultra-light format

Very high breathability – ideal during high intensity

Weighs approximately 72 g – almost non-existent pack weight

Insulates even when wet – safe function in humid environments

Perfect with shell garments – unbeatable warmth-to-weight in layers

Valley-to-peak function – customizable throughout the entire trip

Features

Synthetic insulation vest

PrimaLoft® Active insulation (75 g/m²)

Flatlock seams positioned away from the shoulders for reduced chafing

Softly rolled collar

Reflective logo

Very low bulk – easy to combine with other layers

Technical specifications

Weight : approx. 72 g (M)

Insulation : PrimaLoft® Active 75 g/m²

Material : PrimaLoft® Active mesh construction

Fit : Fitted / Performance

Sustainability : 58% recycled material , Bluesign® & OEKO‑TEX® certified

Sizes : XS – XL

Suitable for

Mountain running, fastpacking, ultra-running, Mountain Marathons and intense mountain tours – when you want maximum warmth around the core of your torso without risking overheating .

Care instructions

Wash according to manufacturer's instructions. Air dry. Store uncompressed for best insulation performance.

Never tried OMM before or just need a little help finding the right size? You can find size charts and help finding the right fit HERE!