the OMM Core Liner

the OMM Core Liner

See our entire range from the OMM here!

The OMM Core Liner is an ultra-lightweight and highly thermally efficient sleeping bag liner , designed to extend the temperature range of your sleeping system on cold nights. It is constructed with PrimaLoft® Active Insulating Fabric Technology , making it one of the warmest synthetic liners for its weight . At the same time, the Core Liner can be used as a stand-alone blanket or lightweight sleeping garment in camp , making it a flexible addition for mountain marathons, ultras and fastpacking.

PrimaLoft® Active blurs the line between fabric and insulation by weaving insulating fibers through an ultra-lightweight mesh material . The result is a material that is warmer than traditional fleece but weighs less than half as much , with down-like performance when dry and continued insulation when damp. This makes Core Liner ideal for wet and variable conditions, where extra warmth is needed without adding a lot of bulk.

The Core Liner has a generous opening and a 3D hood , which allows you to sit completely inside the liner with your arms free – perfect for cooking or resting in the tent. When the temperature drops, the hood can be pulled tight around your face for maximum warmth. The mummy-shaped fit provides effective warmth around the body while the stretch of the material means it never feels constricting.

Weighing in at around 175 grams and packing very small, the Core Liner is an obvious choice for gram hunters looking to add warmth to their sleeping system without switching to a heavier sleeping bag . It is also a valued addition to OMM's modular sleep system , where layer upon layer provides flexibility depending on the weather and season.

Features & Benefits

PrimaLoft® Active insulation – extreme warmth to weight ratio

Ultralight (~175g) – minimal impact on pack weight

Insulates even in moisture – reliable performance in wet conditions

Usable as a blanket – practical for camping

3D hood – can be closed around the face for extra warmth

Stretchy and comfortable – doesn't feel tight

Features

Sleeping bag liner in mummy shape

PrimaLoft® Active 75 g/m²

Large opening for seated use

Adjustable 3D hood

Quick-drying and easy-care

Suspension loops

Packing bag included

Technical specifications

Weight : approx. 175 g (Regular)

Length : approx. 190 cm

Shoulder width : approx. 65 cm

Package size : approx. 16 × 11 cm

Insulation : PrimaLoft® Active 75 g/m²

TOG value : 0.7 dry / 0.4 wet

Material : PrimaLoft® Active mesh with insulating fibers

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

Suitable for

Mountain marathons, ultra races, fastpacking and overnight mountain stays – for those who want to enhance their sleeping system with maximum warmth at minimal weight .

Care instructions

Can be washed according to manufacturer's instructions. Air dry and store uncompressed for best lifespan.