An ultra lightweight insulating mid-layer, OMM's Core jacket uses Primaloft® Next fabric for outstanding breathability and about half the weight of a comparably warm synthetic insulation product. This adaptable full zip jacket is suited to activities requiring different levels of exertion. Created by weaving a Primaloft fibres directly onto a single layer mesh fabric, the high volume and open grid structure will trap heat under a shell or vent excess heat when you wear it as an outer layer. Core Jacket - Men's