OMM Core Running Vest A new concept in active insulation for use as a super warm first layer in the coldest of events and challenges from the OMM to the Spine and the Yukon Ultra. The OMM Core range is made from Primaloft Active ultra-light insulating fabric. Made entirely from Primaloft Active insulating fabric, the Core Vest offers the warmth of a fleece, but in less than half the weight. The Core range is an incredibly effective insulator, but thanks to near-total air permeability, the build-up of heat dissipates. The vest uses the 75g weight Core fabric which provides extra warmth on wintery, or long runs. The Core materials work during wet or dry weather, providing incredible wicking properties, ensuring you don't stay wet for too long. Alongside this, the fabrics will continue to insulate you, even when you're wet. Flatlock seams are positioned away from shoulders, to ensure you feel comfortable, and a soft rolled collar sits comfortably against the skin. Lastl