the OMM Mountain Core Jacket

the OMM Mountain Core Jacket

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The OMM Mountain Core Jacket is a high-performance insulated jacket designed for variable intensity activities in mountain and trail environments . By combining PrimaLoft® Active insulation with OMM's own lightweight, stretchy and windproof Flexile shell , the Mountain Core creates a garment that provides reliable warmth without compromising breathability .

PrimaLoft® Active is a synthetic “down-like” fiber woven through an open knit mesh , creating a high-loft structure with effective insulation. The result is fleece-like warmth at less than half the weight , while allowing excess heat and moisture to escape at higher intensities. This makes Mountain Core ideal for fast climbs, mixed tempo sections and chilly descents.

Like OMM’s other Core products, the Mountain Core is designed to perform both wet and dry . Synthetic insulation combined with excellent moisture transport means the jacket continues to warm even in damp weather. With 125 g/m² PrimaLoft® Active , with approximately 64-65% of the insulation coming from recycled materials , performance is combined with a more sustainable material choice. The insulation is also bluesign® and OEKO-TEX® approved .

The stretchy Flexile nylon/spandex shell provides high wind resistance and some water repellency , while maintaining good ventilation – perfect for changing conditions. The Mountain Core is designed to work alone in dry, cold weather , or under a shell in rain and strong winds for added protection and insulation.

A softly lined hood with a discreet visor provides extra comfort and protection against cold winds, and the jacket's functional details make it an obvious choice for mountain running, trail running and long days in chilly environments.

Features & Benefits

PrimaLoft® Active 125 g/m² – warm, lightweight and extremely breathable insulation

Warm even when wet – synthetic insulation for demanding environments

Flexile shell (nylon/spandex) – wind resistant, stretchy and flexible

High breathability – for activities of varying intensity

Lined hood with soft peak – protection against cold winds

Can be combined with a shell jacket – maximum flexibility in bad weather

Features

Stretch panels

Wind-resistant construction

Warm even in humid conditions

Large fleece-lined hand pockets

Hidden zippered chest/inner compartment with key clip

Full-length YKK® zipper

Fleece-lined hood with soft peak

Technical details

Insulation : PrimaLoft® Active 125 g/m²

Recycled content : approx. 64–65%

Material (outer fabric) : Flexile (nylon/spandex blend)

Surface treatment : DWR (Durable Water Repellent)

Weight : approx. 400 g (size M)

Suitable for

Trail running, mountain running, hiking, mountain tours and active days in cold, windy and changeable weather , where you need insulating warmth that breathes while moving .

Care instructions

Wash according to manufacturer's instructions. Avoid fabric softener to preserve the function of the insulation and DWR treatment.

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!