the OMM Mountain Core 125

the OMM Mountain Core 125

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The OMM Mountain Core 125 is an extremely lightweight and comfort-focused synthetic sleeping bag , developed for warm to mild conditions, summer use and gram hunting in contexts such as Mountain Marathons, ultra races and fastpacking . With a focus on ventilation, skin comfort and low weight, it offers an alternative to the warmer Raid models when temperatures allow.

The sleeping bag uses PrimaLoft® Active (125 g/m²) as the inner structure, which provides an open, fleece-like feel against the skin but with a significantly better warmth-to-weight ratio than traditional fleece. This material is exceptionally breathable , reduces the trapped feeling that can occur in classic sleeping bags and creates a comfortable sleeping climate even on warmer nights .

PrimaLoft® Active also continues to insulate even when damp , making the Mountain Core 125 a reliable choice for nights with condensation, light precipitation or high humidity. OMM lists a TOG value of 1.4 when dry and 1.0 when wet , clearly positioning it as a summer sleeping bag with reliable moisture performance .

The outer material is OMM's PointZero® nylon , a very lightweight yet windproof and durable water repellent (DWR) fabric that protects against drafts and external moisture without sacrificing packability. The construction maintains the compact pack size you expect from OMM - perfect when every liter of your pack counts.

The Mountain Core 125 features a mummy fit , shaped foot box and half-length YKK zipper for weight saving and easy temperature regulation. With a total weight of only about 380 grams , this is one of the lightest full-length sleeping bags in the OMM range .

Features & Benefits

Extremely light weight (~380 g) – perfect for gram hunters

PrimaLoft® Active 125 g/m² – high breathability and skin comfort

Reduces clamminess – comfortable sleeping climate in warmer weather

Insulates even when damp – reliable performance in the event of condensation

Windproof PointZero® shell with DWR – protection without unnecessary weight

Very compact pack size – ideal for racing and fastpacking

Features

PrimaLoft® Active insulation (125 g/m²)

Mummy-shaped fit

Half-length YKK® zipper

Adjustable hood with drawstring

Shaped foot box

Quick-drying and easy-care material

Hanging loops for drying

Technical specifications

Weight : approx. 380 g (Regular)

Insulation : PrimaLoft® Active 125 g/m²

TOG value : 1.4 dry / 1.0 wet

Length : approx. 195 cm

Shoulder width : approx. 65 cm

Foot width : approx. 35 cm

Package size : approx. 21 × 13 cm

Material : PointZero® nylon with DWR

Suitable for

Summer overnight stays, warm nights, ultra races, mountain marathons and fastpacking – when low weight, ventilation and comfort are more important than maximum warmth.

Care instructions

Wash according to manufacturer's instructions. Air dry and store uncompressed for best lifespan.